Some Basic Concepts of Chemistry · Chemistry · JEE Main

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MCQ (Single Correct Answer)

1

$$ \text { Match List - I with List - II. } $$

List - I
Mass of substance
List - II
Number of atoms
A. 1.8 mg water I. $$
2 \times 10^{-4} \times \mathrm{N}_{\mathrm{A}}
$$
B. 9.8 mg sulphuric acid II. $$
1.5 \times 10^{-4} \times \mathrm{N}_{\mathrm{A}}
$$
C. 1.8 mg carbon III. $$
3 \times 10^{-4} \times \mathrm{N}_{\mathrm{A}}
$$
D. 5.85 mg salt $(\mathrm{NaCl})$ IV. $$
7 \times 10^{-4} \times \mathrm{N}_{\mathrm{A}}
$$

$$ \text { Choose the correct answer from the options given below : } $$

JEE Main 2026 (Online) 8th April Evening Shift
2

Which of the following contain the same number of atoms?

(Given : Molar mass in $\mathrm{g} \mathrm{mol}^{-1}$ of $\mathrm{H}, \mathrm{He}, \mathrm{O}$ and S are 1, 4, 16 and 32 respectively)

A. 2 g of $\mathrm{O}_2$ gas

B. 4 g of $\mathrm{SO}_2$ gas

C. 1400 mL of $\mathrm{O}_2$ at STP

D. $0.05 \mathrm{~L}$ of He at STP

E. $ 0.0625 \mathrm{~mol}$ of $\mathrm{H}_2$ gas

Choose the correct answer from the options given below :

JEE Main 2026 (Online) 6th April Evening Shift
3

An oxide of iron contains $69.9 \%$ iron, its empirical formula, is :

(Given : Molar mass of Fe and O are 56 and $16 \mathrm{~g} \mathrm{~mol}^{-1}$ respectively.)

JEE Main 2026 (Online) 6th April Morning Shift
4

What volume of hydrogen gas at STP would be liberated by action of 50 mL of $\mathrm{H}_2 \mathrm{SO}_4$ of $50 \%$ purity (density $=1.3 \mathrm{~g} \mathrm{~mL}^{-1}$ ) on 20 g of zinc?

Given : Molar mass of $\mathrm{H}, \mathrm{O}, \mathrm{S}, \mathrm{Zn}$ are 1, 16, 32, $65 \mathrm{~g} \mathrm{~mol}^{-1}$ respectively.

JEE Main 2026 (Online) 5th April Evening Shift
5

How many grams of residue is obtained by heating 2.76 g of silver carbonate?

(Given : Molar mass of $\mathrm{C}, \mathrm{O}$ and Ag are 12, 16 and $108 \mathrm{~g} \mathrm{~mol}^{-1}$ respectively)

JEE Main 2026 (Online) 5th April Morning Shift
6

What is the mole fraction of water in $10 \%$ by weight $(\mathrm{w} / \mathrm{w})$ of aqueous urea solution?

[Given: Molar mass of $\mathrm{H}, \mathrm{O}, \mathrm{C}$ and N are $1,16,12$ and $14 \mathrm{~g} \mathrm{~mol}^{-1}$ respectively.]

JEE Main 2026 (Online) 5th April Morning Shift
7

The correct order of total number of atoms present in

(A) 2 moles of cyclohexane

(B) 684 g of sucrose

(C) 90.8 L of dihydrogen at STP

is :

JEE Main 2026 (Online) 4th April Evening Shift
8

Number of moles and number of molecules in 1.4187 L of $\mathrm{SO}_2$ at STP respectively are

JEE Main 2026 (Online) 4th April Morning Shift
9

The ratio of mass percentage (w/w) of C : H in a hydrocarbon is 12 : 1. It has two carbon atoms. The weight (in g) of CO2(g) formed when 3.38 g of this hydrocarbon is completely burnt in oxygen is :

(Given : Molar mass in g mol–1 C : 12, H : 1, O : 16)

JEE Main 2026 (Online) 2nd April Evening Shift
10

The mass of iron converted into Fe3O4 by the action of 18 g of steam is:

(Given: Molar mass of H, O and Fe are 1, 16 and 56 g mol−1 respectively)

Assume iron is present in excess:

JEE Main 2026 (Online) 2nd April Morning Shift
11

For the given reaction;

CaCO3 + 2HCl → CaCl2 + H2O + CO2

If 90 g CaCO3 is added to 300 mL of HCl which contains 38.55% HCl by mass and has density 1.13 g mL−1, then which of the following option is correct?

Given molar mass of H, Cl, Ca and O are 1, 35.5, 40 and 16 g mol−1 respectively.

JEE Main 2026 (Online) 28th January Evening Shift
12

Identify the correct statements :

A. Hydrated salts can be used as primary standard.

B. Primary standard should not undergo any reaction with air.

C. Reactions of primary standard with another substance should be instantaneous and stoichiometric.

D. Primary standard should not be soluble in water.

E. Primary standard should have low relative molar mass.

Choose the correct answer from the options given below :

JEE Main 2026 (Online) 22nd January Evening Shift
13

$\mathrm{A}+2 \mathrm{~B} \longrightarrow \mathrm{AB}_2$

36.0 g of 'A' (Molar mass : $60 \mathrm{~g} \mathrm{~mol}^{-1}$ ) and 56.0 g of ' B ' (Molar mass : $80 \mathrm{~g} \mathrm{~mol}^{-1}$ ) are allowed to react. Which of the following statements are correct ?

A. 'A' is the limiting reagent.

B. $77.0 \mathrm{~g}$ of $\mathrm{AB}_2$ is formed.

C. Molar mass of $\mathrm{AB}_2$ is $140 \mathrm{~g} \mathrm{~mol}^{-1}$.

D. $15.0 \mathrm{~g}$ of A is left unreacted after the completion of reaction.

Choose the correct answer from the options given below :

JEE Main 2026 (Online) 22nd January Evening Shift
14

In the reaction,

$$ 2 \mathrm{Al}(\mathrm{~s})+6 \mathrm{HCl}(\mathrm{aq}) \rightarrow 2 \mathrm{Al}^{3+}(\mathrm{aq})+6 \mathrm{Cl}^{-}(\mathrm{aq})+3 \mathrm{H}_2(\mathrm{~g}) $$

JEE Main 2026 (Online) 22nd January Morning Shift
15

By usual analysis, 1.00 g of compound (X) gave 1.79 g of magnesium pyrophosphate. The percentage of phosphorus in compound (X) is : (nearest integer)

(Given, molar mass in g mol−1: O = 16, Mg = 24, P = 31)

JEE Main 2026 (Online) 21st January Evening Shift
16

Aqueous HCl reacts with MnO2(s) to form MnCl2(aq), Cl2(g), and H2O(l). What is the weight (in g) of Cl2 liberated when 8.7 g of MnO2(s) is reacted with excess aqueous HCl solution? (Given Molar mass in g mol−1 Mn = 55, Cl = 35.5, O = 16, H = 1)

JEE Main 2026 (Online) 21st January Evening Shift
17

14.0 g of calcium metal is allowed to react with excess HCl at 1.0 atm pressure and 273 K . Which of the following statements is incorrect?

[Given : Molar mass in $\mathrm{g} \mathrm{mol}^{-1}$ of $\mathrm{Ca}-40, \mathrm{Cl}-35.5, \mathrm{H}-1$ ]

JEE Main 2026 (Online) 21st January Morning Shift
18

On combustion 0.210 g of an organic compound containing C, H and O gave 0.127 g H2O and 0.307 g CO2. The percentages of hydrogen and oxygen in the given organic compound respectively are:

JEE Main 2025 (Online) 8th April Evening Shift
19

Mass of magnesium required to produce 220 mL of hydrogen gas at STP on reaction with excess of dil. HCl is

Given: Molar mass of Mg is $24 \mathrm{~g} \mathrm{~mol}^{-1}$.

JEE Main 2025 (Online) 3rd April Evening Shift
20

10 mL of 2 M NaOH solution is added to 20 mL of 1 M HCl solution kept in a beaker. Now, 10 mL of this mixture is poured into a volumetric flask of 100 mL containing 2 moles of HCl and made the volume upto the mark with distilled water. The solution in this flask is :

JEE Main 2025 (Online) 3rd April Evening Shift
21
In Dumas' method for estimation of nitrogen 0.4 g of an organic compound gave 60 mL of nitrogen collected at 300 K temperature and 715 mm Hg pressure. The percentage composition of nitrogen in the compound is (Given : Aqueous tension at $300 \mathrm{~K}=15 \mathrm{~mm} \mathrm{Hg}$ )
JEE Main 2025 (Online) 3rd April Evening Shift
22

Among $10^{-9} \mathrm{~g}$ (each) of the following elements, which one will have the highest number of atoms?

Element: $\mathrm{Pb}, \mathrm{Po}, \mathrm{Pr}$ and Pt

JEE Main 2025 (Online) 3rd April Morning Shift
23

$$\mathrm{CaCO}_3(\mathrm{~s})+2 \mathrm{HCl}(\mathrm{aq}) \rightarrow \mathrm{CaCl}_2(\mathrm{aq})+\mathrm{CO}_2(\mathrm{~g})+\mathrm{H}_2 \mathrm{O}(\mathrm{l})$$

Consider the above reaction, what mass of $\mathrm{CaCl}_2$ will be formed if 250 mL of 0.76 M HCl reacts with 1000 g of $\mathrm{CaCO}_3$ ?

(Given : Molar mass of $\mathrm{Ca}, \mathrm{C}, \mathrm{O}, \mathrm{H}$ and Cl are $40,12,16,1$ and $35.5 \mathrm{~g} \mathrm{~mol}^{-1}$, respectively)

JEE Main 2025 (Online) 2nd April Morning Shift
24

On complete combustion 1.0 g of an organic compound $(\mathrm{X})$ gave 1.46 g of $\mathrm{CO}_2$ and 0.567 g of $\mathrm{H}_2 \mathrm{O}$. The empirical formula mass of compound $(\mathrm{X})$ is __________ g. (Given molar mass in $\mathrm{g} \mathrm{mol}^{-1} \mathrm{C}: 12, \mathrm{H}: 1, \mathrm{O}: 16$ )

JEE Main 2025 (Online) 2nd April Morning Shift
25

Choose the correct statements.

(A) Weight of a substance is the amount of matter present in it.

(B) Mass is the force exerted by gravity on an object.

(C) Volume is the amount of space occupied by a substance.

(D) Temperatures below 0°C are possible in Celsius scale, but in Kelvin scale negative temperature is not possible.

(E) Precision refers to the closeness of various measurements for the same quantity.

Choose the correct answer from the options given below :

JEE Main 2025 (Online) 29th January Morning Shift
26

Concentrated nitric acid is labelled as $75 \%$ by mass. The volume in mL of the solution which contains 30 g of nitric acid is ______________.

Given : Density of nitric acid solution is $1.25 \mathrm{~g} / \mathrm{mL}$.

JEE Main 2025 (Online) 28th January Evening Shift
27

The elemental composition of a compound is $54.2 \% \mathrm{C}, 9.2 \% \mathrm{H}$ and $36.6 \% \mathrm{O}$. If the molar mass of the compound is $132 \mathrm{~g} \mathrm{~mol}^{-1}$, the molecular formula of the compound is : [Given : The relative atomic mass of $\mathrm{C}: \mathrm{H}: \mathrm{O}=12: 1: 16$ ]

JEE Main 2025 (Online) 24th January Evening Shift
28

$2.8 \times 10^{-3} \mathrm{~mol}$ of $\mathrm{CO}_2$ is left after removing $10^{21}$ molecules from its ' $x$ ' mg sample. The mass of $\mathrm{CO}_2$ taken initially is Given: $\mathrm{N}_{\mathrm{A}}=6.02 \times 10^{23} \mathrm{~mol}^{-1}$

JEE Main 2025 (Online) 23rd January Morning Shift
29

Density of 3 M NaCl solution is $1.25 \mathrm{~g} / \mathrm{mL}$. The molality of the solution is :

JEE Main 2025 (Online) 22nd January Evening Shift
30

Combustion of glucose $$(\mathrm{C}_6 \mathrm{H}_{12} \mathrm{O}_6)$$ produces $$\mathrm{CO}_2$$ and water. The amount of oxygen (in $$\mathrm{g}$$) required for the complete combustion of $$900 \mathrm{~g}$$ of glucose is :

[Molar mass of glucose in $$\mathrm{g} \mathrm{~mol}^{-1}=180$$]

JEE Main 2024 (Online) 8th April Morning Shift
31

Molality $$(\mathrm{m})$$ of $$3 \mathrm{M}$$ aqueous solution of $$\mathrm{NaCl}$$ is : (Given : Density of solution $$=1.25 \mathrm{~g} \mathrm{~mL}^{-1}$$, Molar mass in $$\mathrm{g} \mathrm{~mol}^{-1}: \mathrm{Na}-23, \mathrm{Cl}-35.5$$)

JEE Main 2024 (Online) 6th April Evening Shift
32

The density of '$$x$$' $$\mathrm{M}$$ solution ('$$x$$' molar) of $$\mathrm{NaOH}$$ is $$1.12 \mathrm{~g} \mathrm{~mL}^{-1}$$, while in molality, the concentration of the solution is $$3 \mathrm{~m}$$ ( 3 molal). Then $$x$$ is

(Given : Molar mass of $$\mathrm{NaOH}$$ is $$40 \mathrm{~g} / \mathrm{mol}$$)

JEE Main 2024 (Online) 6th April Morning Shift
33

The number of moles of methane required to produce $$11 \mathrm{~g} \mathrm{~CO}_2(\mathrm{g})$$ after complete combustion is : (Given molar mass of methane in $$\mathrm{g} \mathrm{~mol}^{-1}: 16$$ )

JEE Main 2024 (Online) 5th April Evening Shift
34

An organic compound has $$42.1 \%$$ carbon, $$6.4 \%$$ hydrogen and remainder is oxygen. If its molecular weight is 342 , then its molecular formula is :

JEE Main 2024 (Online) 5th April Morning Shift
35

The Molarity (M) of an aqueous solution containing $$5.85 \mathrm{~g}$$ of $$\mathrm{NaCl}$$ in $$500 \mathrm{~mL}$$ water is : (Given : Molar Mass $$\mathrm{Na}: 23$$ and $$\mathrm{Cl}: 35.5 \mathrm{~gmol}^{-1}$$)

JEE Main 2024 (Online) 4th April Morning Shift
36

A sample of $$\mathrm{CaCO}_3$$ and $$\mathrm{MgCO}_3$$ weighed $$2.21 \mathrm{~g}$$ is ignited to constant weight of $$1.152 \mathrm{~g}$$. The composition of mixture is :

(Given molar mass in $$\mathrm{g} \mathrm{~mol}^{-1} \mathrm{CaCO}_3: 100, \mathrm{MgCO}_3: 84$$)

JEE Main 2024 (Online) 31st January Evening Shift
37

If a substance '$$A$$' dissolves in solution of a mixture of '$$B$$' and '$$C$$' with their respective number of moles as $$\mathrm{n}_{\mathrm{A}}, \mathrm{n}_{\mathrm{B}}$$ and $$\mathrm{n}_{\mathrm{C}_3}$$. Mole fraction of $$\mathrm{C}$$ in the solution is

JEE Main 2024 (Online) 30th January Evening Shift
38

The quantity which changes with temperature is :

JEE Main 2024 (Online) 27th January Evening Shift
39

A metal chloride contains $$55.0 \%$$ of chlorine by weight . $$100 \mathrm{~mL}$$ vapours of the metal chloride at STP weigh $$0.57 \mathrm{~g}$$. The molecular formula of the metal chloride is

(Given: Atomic mass of chlorine is $$35.5 \mathrm{u}$$)

JEE Main 2023 (Online) 12th April Morning Shift
40

A solution is prepared by adding $$2 \mathrm{~g}$$ of "$$\mathrm{X}$$" to 1 mole of water. Mass percent of "$$\mathrm{X}$$" in the solution is :

JEE Main 2023 (Online) 11th April Evening Shift
41

Given below are two statements: one is labelled as Assertion $$\mathbf{A}$$ and the other is labelled as Reason $$\mathbf{R}$$

Assertion A : $$3.1500 \mathrm{~g}$$ of hydrated oxalic acid dissolved in water to make $$250.0 \mathrm{~mL}$$ solution will result in $$0.1 \mathrm{~M}$$ oxalic acid solution.

Reason $$\mathbf{R}$$ : Molar mass of hydrated oxalic acid is $$126 \mathrm{~g} \mathrm{~mol}^{-1}$$

In the light of the above statements, choose the correct answer from the options given below.

JEE Main 2023 (Online) 10th April Evening Shift
42

Match List I with List II

List - I List - II ($$\Delta_0$$)
A. 16 g of $$\mathrm{CH_4~(g)}$$ I. Weighs 28 g
B. 1 g of $$\mathrm{H_2~(g)}$$ II. $$60.2\times10^{23}$$ electrons
C. 1 mole of $$\mathrm{N_2~(g)}$$ III. Weighs 32 g
D. 0.5 mol of $$\mathrm{SO_2~(g)}$$ IV. Occupies 11.4 L volume of STP

Choose the correct answer from the options given below:

JEE Main 2023 (Online) 10th April Evening Shift
43

The number of molecules and moles in 2.8375 litres of O$$_2$$ at STP are respectively

JEE Main 2023 (Online) 10th April Morning Shift
44

Which of the following have same number of significant figures?

A. 0.00253

B. 1.0003

C. 15.0

D. 163

Choose the correct answer from the options given below

JEE Main 2023 (Online) 8th April Evening Shift
45

The volume of $$0.02 ~\mathrm{M}$$ aqueous $$\mathrm{HBr}$$ required to neutralize $$10.0 \mathrm{~mL}$$ of $$0.01 ~\mathrm{M}$$ aqueous $$\mathrm{Ba}(\mathrm{OH})_{2}$$ is (Assume complete neutralization)

JEE Main 2023 (Online) 6th April Evening Shift
46
When a hydrocarbon A undergoes complete combustion it requires 11 equivalents of oxygen and produces 4 equivalents of water. What is the molecular formula of $A$ ?
JEE Main 2023 (Online) 31st January Evening Shift
47
$1 \mathrm{~L}, 0.02 \mathrm{M}$ solution of $\left[\mathrm{Co}\left(\mathrm{NH}_{3}\right)_{5} \mathrm{SO}_{4}\right]$ Br is mixed with $1 \mathrm{~L}, 0.02 \mathrm{M}$ solution of $\left[\mathrm{Co}\left(\mathrm{NH}_{3}\right)_{5} \mathrm{Br}\right] \mathrm{SO}_{4}$. The resulting solution is divided into two equal parts $(\mathrm{X})$ and treated with excess of $\mathrm{AgNO}_{3}$ solution and $\mathrm{BaCl}_{2}$ solution respectively as shown below:

$1 \mathrm{~L}$ Solution $(\mathrm{X})+\mathrm{AgNO}_{3}$ solution (excess) $\longrightarrow \mathrm{Y}$

$1 \mathrm{~L}$ Solution $(\mathrm{X})+\mathrm{BaCl}_{2}$ solution (excess) $\longrightarrow \mathrm{Z}$

The number of moles of $\mathrm{Y}$ and $\mathrm{Z}$ respectively are
JEE Main 2023 (Online) 30th January Evening Shift
48

When a hydrocarbon A undergoes combustion in the presence of air, it requires 9.5 equivalents of oxygen and produces 3 equivalents of water. What is the molecular formula of A?

JEE Main 2023 (Online) 29th January Evening Shift
49

What is the mass ratio of ethylene glycol ($$\mathrm{C_2H_6O_2}$$, molar mass = 62 g/mol) required for making 500 g of 0.25 molal aqueous solution and 250 mL of 0.25 molar aqueous solution?

JEE Main 2023 (Online) 25th January Evening Shift
50

'25 volume' hydrogen peroxide means

JEE Main 2023 (Online) 25th January Morning Shift
51

Consider the reaction

$$4 \mathrm{HNO}_{3}(1)+3 \mathrm{KCl}(\mathrm{s}) \rightarrow \mathrm{Cl}_{2}(\mathrm{~g})+\mathrm{NOCl}(\mathrm{g})+2 \mathrm{H}_{2} \mathrm{O}(\mathrm{g})+3 \mathrm{KNO}_{3}(\mathrm{~s})$$

The amount of $$\mathrm{HNO}_{3}$$ required to produce $$110.0 \mathrm{~g}$$ of $$\mathrm{KNO}_{3}$$ is

(Given: Atomic masses of $$\mathrm{H}, \mathrm{O}, \mathrm{N}$$ and $$\mathrm{K}$$ are $$1,16,14$$ and 39, respectively.)

JEE Main 2022 (Online) 29th July Evening Shift
52

$$ \begin{aligned} &\mathrm{C}(\mathrm{s})+\mathrm{O}_{2}(\mathrm{~g}) \rightarrow \mathrm{CO}_{2}(\mathrm{~g})+400 \mathrm{~kJ} \\ &\mathrm{C}(\mathrm{s})+\frac{1}{2} \mathrm{O}_{2}(\mathrm{~g}) \rightarrow \mathrm{CO}(\mathrm{g})+100 \mathrm{~kJ} \end{aligned} $$

When coal of purity 60% is allowed to burn in presence of insufficient oxygen, 60% of carbon is converted into 'CO' and the remaining is converted into '$$\mathrm{CO}_{2}$$'. The heat generated when $$0.6 \mathrm{~kg}$$ of coal is burnt is _________.

JEE Main 2022 (Online) 29th July Evening Shift
53

$$ \mathrm{N}_{2(\mathrm{~g})}+3 \mathrm{H}_{2(\mathrm{~g})} \rightleftharpoons 2 \mathrm{NH}_{3(\mathrm{~g})} $$

$$20 \mathrm{~g} \quad ~~~5 \mathrm{~g}$$

Consider the above reaction, the limiting reagent of the reaction and number of moles of $$\mathrm{NH}_{3}$$ formed respectively are :

JEE Main 2022 (Online) 29th July Morning Shift
54

$$250 \mathrm{~g}$$ solution of $$\mathrm{D}$$-glucose in water contains $$10.8 \%$$ of carbon by weight. The molality of the solution is nearest to

(Given: Atomic Weights are, $$\mathrm{H}, 1 \,\mathrm{u} ; \mathrm{C}, 12 \,\mathrm{u} ; \mathrm{O}, 16 \,\mathrm{u}$$)

JEE Main 2022 (Online) 27th July Morning Shift
55

In Carius method of estimation of halogen, $$0.45 \mathrm{~g}$$ of an organic compound gave $$0.36 \mathrm{~g}$$ of $$\mathrm{AgBr}$$. Find out the percentage of bromine in the compound.

(Molar masses : $$\mathrm{AgBr}=188 \mathrm{~g} \mathrm{~mol}^{-1} ; \mathrm{Br}=80 \mathrm{~g} \mathrm{~mol}^{-1}$$)

JEE Main 2022 (Online) 27th July Morning Shift
56

Hemoglobin contains $$0.34 \%$$ of iron by mass. The number of Fe atoms in $$3.3 \mathrm{~g}$$ of hemoglobin is

(Given: Atomic mass of Fe is $$56 \,\mathrm{u}, \mathrm{N}_{\mathrm{A}}=6.022 \times 10^{23} \mathrm{~mol}^{-1}$$.)

JEE Main 2022 (Online) 26th July Evening Shift
57

$$\mathrm{SO}_{2} \mathrm{Cl}_{2}$$ on reaction with excess of water results into acidic mixture

$$\mathrm{SO}_{2} \mathrm{Cl}_{2}+2 \mathrm{H}_{2} \mathrm{O} \rightarrow \mathrm{H}_{2} \mathrm{SO}_{4}+2 \mathrm{HCl}$$

16 moles of $$\mathrm{NaOH}$$ is required for the complete neutralisation of the resultant acidic mixture. The number of moles of $$\mathrm{SO}_{2} \mathrm{Cl}_{2}$$ used is :

JEE Main 2022 (Online) 25th July Morning Shift
58

Using the rules for significant figures, the correct answer for the expression $${{0.02858 \times 0.112} \over {0.5702}}$$ will be

JEE Main 2022 (Online) 29th June Evening Shift
59

Production of iron in blast furnace follows the following equation

Fe3O4(s) + 4CO(g) $$\to$$ 3Fe(l) + 4CO2(g)

when 4.640 kg of Fe3O4 and 2.520 kg of CO are allowed to react then the amount of iron (in g) produced is :

[Given : Molar Atomic mass (g mol$$-$$1) : Fe = 56, Molar Atomic mass (g mol$$-$$1) : O = 16, Molar Atomic mass (g mol$$-$$1) : C = 12]

JEE Main 2022 (Online) 29th June Morning Shift
60

Compound A contains 8.7% Hydrogen, 74% Carbon and 17.3% Nitrogen. The molecular formula of the compound is,

Given : Atomic masses of C, H and N are 12, 1 and 14 amu respectively.

The molar mass of the compound A is 162 g mol$$-$$1.

JEE Main 2022 (Online) 28th June Evening Shift
61

A commercially sold conc. HCl is 35% HCl by mass. If the density of this commercial acid is 1.46 g/mL, the molarity of this solution is:

(Atomic mass : Cl = 35.5 amu, H = 1 amu)

JEE Main 2022 (Online) 26th June Morning Shift
62

120 g of an organic compound that contains only carbon and hydrogen gives 330 g of CO2 and 270 g of water on complete combustion. The percentage of carbon and hydrogen, respectively are

JEE Main 2022 (Online) 24th June Evening Shift
63

If a rocket runs on a fuel (C15H30) and liquid oxygen, the weight of oxygen required and CO2 released for every litre of fuel respectively are :

(Given : density of the fuel is 0.756 g/mL)

JEE Main 2022 (Online) 24th June Morning Shift
64
The exact volumes of 1 M NaOH solution required to neutralise 50 mL of 1 M H3PO3 solution and 100 mL of 2 M H3PO2 solution, respectively, are :
JEE Main 2021 (Online) 16th March Evening Shift
65
Complete combustion of 1.80 g of an oxygen containing compound (CxHyOz) gave 2.64 g of CO2 and 1.08 g of H2O. The percentage of oxygen in the organic compound is :
JEE Main 2021 (Online) 25th February Morning Shift
66
The average molar mass of chlorine is 35.5 g mol–1. The ratio of 35Cl to 37Cl in naturally occuring chlorine is close to :
JEE Main 2020 (Online) 6th September Evening Slot
67
A solution of two components containing n1 moles of the 1st component and n2 moles of the 2nd component is prepared. M1 and M2 are the molecular weights of component 1 and 2 respectively. If d is the density of the solution in g mL–1, C2 is the molarity and x2 is the mole fraction of the 2nd component, then C2 can be expressed as :
JEE Main 2020 (Online) 6th September Morning Slot
68
The strengths of 5.6 volume hydrogen peroxide (of density 1 g/mL) in terms of mass percentage and molarity (M), respectively, are: (Take molar mass of hydrogen peroxide as 34 g/mol)
JEE Main 2020 (Online) 3rd September Evening Slot
69
The ammonia (NH3) released on quantitative reaction of 0.6 g urea (NH2CONH2) with sodium hydroxide (NaOH) can be neutralized by :
JEE Main 2020 (Online) 7th January Evening Slot
70
Amongst the following statements, that which was not proposed by Dalton was :
JEE Main 2020 (Online) 7th January Morning Slot
71
25 g of an unknown hydrocarbon upon burning produces 88 g of CO2 and 9 g of H2O. This unknown hydrocarbon contains :
JEE Main 2019 (Online) 12th April Evening Slot
72
Thermal decomposition of a Mn compound (X) at 513 K results in compound Y, MnO2 and gaseous product. MnO2 reacts with NaCl and concentrated H2O4 to give a pungent gas Z. X, Y and Z, respectively, are :
JEE Main 2019 (Online) 12th April Evening Slot
73
The mole fraction of a solvent in aqueous solution of a solute is 0.8. The molality (in mol kg–1 ) of the aqueous solution is :
JEE Main 2019 (Online) 12th April Morning Slot
74
5 moles of AB2 weigh 125 × 10–3 kg and 10 moles of A2B2 weigh 300 × 10–3 kg. The molar mass of A (MA) and molar mass of B (MB) in kg mol are:
JEE Main 2019 (Online) 12th April Morning Slot
75
The minimum amount of O2(g) consumed per gram of reactant is for the reaction :
(Given atomic mass : Fe = 56, O = 16, Mg = 24, P = 31, C = 12, H = 1)
JEE Main 2019 (Online) 10th April Evening Slot
76
At 300 K and 1 atmospheric pressure, 10 mL of a hydrocarbon required 55 mL of O2 for complete combustion, and 40 mL of CO2 is formed. The formula of the hydrocarbon is :
JEE Main 2019 (Online) 10th April Morning Slot
77
What would be the molality of 20% (mass/ mass) aqueous solution of KI?
(molar mass of KI = 166 g mol–1)
JEE Main 2019 (Online) 9th April Evening Slot
78
For a reaction,
N2(g) + 3H2(g) $$ \to $$ 2NH3(g) ;
identify dihydrogen (H2) as a limiting reagent in the following reaction mixtures.
JEE Main 2019 (Online) 9th April Morning Slot
79
The percentage composition of carbon by mole in methane is :
JEE Main 2019 (Online) 8th April Evening Slot
80
8 g of NaOH is dissolved in 18g of H2O. Mole fraction of NaOH in solution and molality (in mol kg–1) of the solution respectively are -
JEE Main 2019 (Online) 12th January Evening Slot
81
25 ml of the given HCl solution requires 30 mL of 0.1 M sodium carbonate solution. What is the volume of this HCl solution required to titrate 30 mL of 0.2 M aqueous NaOH solutions ?
JEE Main 2019 (Online) 11th January Evening Slot
82
An organic compound is estimated through Duma's method and was found to evolve 6 moles of CO2. 4 moles of H2O and 1 mole of nitrogen gas. The formula of the compound is :
JEE Main 2019 (Online) 11th January Morning Slot
83
A 10 mg effervescent tablet containing sodium bicarbonate and oxalic acid releases 0.25 ml of CO2 at T = 298.15 K and p = 1 bar. If molar volume of CO2 is 25.0 L under such condition, what is the percentage of sodium bicarbonate in each tablet ?
[Molar mass of NaHCO3 = 84 g mol–1]
JEE Main 2019 (Online) 11th January Morning Slot
84
The amount of sugar (C12H22O11) required to prepare 2L of its 0.1 M aqueous solution is :
JEE Main 2019 (Online) 10th January Evening Slot
85
For the following reaction, in the mass of water produced from 445 g of C57H110O6 is :

2C57H110O6(s) + 163 O2(g) $$ \to $$ 114 CO2(g) + 110 H2O(l)
JEE Main 2019 (Online) 9th January Evening Slot
86
A solution of sodium sulphate contains 92 g of Na+ ions per kilogram of water. The molality of Na+ ions in that solution in mol kg$$-$$1 is :
JEE Main 2019 (Online) 9th January Morning Slot
87
An unknown chlorohydrocarbon has 3.55% of chlorine. If each molecule of the hydrocarbon has one chlorine atom only; chlorine atoms present in 1 g of chlorohydrocarbon are :
(Atomic wt. of Cl = 35.5 u; Avogadro constant = 6.023 $$ \times $$ 1023 mol-1)
JEE Main 2018 (Online) 16th April Morning Slot
88
The ratio of mass percent of C and H of an organic compound (CXHYOZ) is 6 : 1. If one molecule of the above compound (CXHYOZ) contains half as much oxygen as required to burn one molecule of compound CXHY completely to CO2 and H2O. The empirical formula of compound CXHYOZ is
JEE Main 2018 (Offline)
89
For per gram of reactant, the maximum quantity of N2 gas is produced in which of the following thermal decomposition reactions ?
(Given : Atomic wt. - Cr = 52 u, Ba = 137 u)
JEE Main 2018 (Online) 15th April Evening Slot
90
A sample of $$NaCl{O_3}$$ is converted by heat to $$NaCl$$ with a loss of $$0.16$$ $$g$$ of oxygen. The residue is dissolved in water and precipitated as $$AgCl.$$ The mass of $$AgCl$$ (in $$g$$) obtained will be : (Given : Molar mass of $$AgCl=143.5$$ $$g$$ $$mo{l^{ - 1}}$$)
JEE Main 2018 (Online) 15th April Morning Slot
91
What quantity (in mL) of a 45% acid solution of a mono-protic strong acid must be mixed with a 20% solution of the same acid to produce 800 mL of a 29.875% acid solution ?
JEE Main 2017 (Online) 9th April Morning Slot
92
Excess of NaOH (aq) was added to 100 mL of FeCl3 (aq) resulting into 2.14 g of Fe(OH)3 . The molarity of FeCl3 (aq) is :

(Given molar mass of Fe = 56 g mol−1 and molar mass of Cl = 35.5 g mol−1)
JEE Main 2017 (Online) 8th April Morning Slot
93
The most abundant elements by mass in the body of a healthy human adult are: Oxygen (61.4%); Carbon (22.9%), Hydrogen (10.0%); and Nitrogen (2.6%). The weight which a 75 kg person would gain if all 1H atoms are replaced by 2H atoms is:
JEE Main 2017 (Offline)
94
1 gram of a carbonate (M2CO3) on treatment with excess HCl produces 0.01186 mole of CO2. The molar mass of M2CO3 in g mol–1 is:
JEE Main 2017 (Offline)
95
An organic compound contains C, H and S. The minimum molecular weight of the compound containing 8% sulphur is :

(atomic weight of S = 32 amu)
JEE Main 2016 (Online) 9th April Morning Slot
96
The amount of arsenic pentasulphide that can be obtained when 35.5 g arsenic acid istreated with excess H2S in the presence of conc. HCl ( assuming 100% conversion) is :
JEE Main 2016 (Online) 9th April Morning Slot
97
The molecular formula of a commercial resin used for exchanging ions in water softening is C8H7SO3Na (Mol. Wt. 206). What would be the maximum uptake of Ca2+ ions by the resin when expressed in mole per gram resin?
JEE Main 2015 (Offline)
98
The ratio of masses of oxygen and nitrogen in a particular gaseous mixture is 1 : 4. The ratio of number of their molecule is:
JEE Main 2014 (Offline)
99
A gaseous hydrocarbon gives upon combustion 0.72 g of water and 3.08 g of CO2. The empirical formula of the hydrocarbon is
JEE Main 2013 (Offline)
100
Experimentally it was found that a metal oxide has formula M0.98O. Metal M, present as M2+ and M3+ in its oxide. Fraction of the metal which exists as M3+ would be
JEE Main 2013 (Offline)
101
The molarity of a solution obtained by mixing 750 mL of 0.5 (M) HCl with 250 mL of 2(M) HCl will be:
JEE Main 2013 (Offline)
102
The density of a solution prepared by dissolving 120 g of urea (mol. Mass = 60 u ) in 1000g of water is 1.15 g/mL. The molarity of this solution is :
AIEEE 2012
103
A 5.2 molal aqueous solution of methyl alcohol, CH3OH, is supplied. What is the mole fraction of methyl alcohol in the solution ?
AIEEE 2011
104
The density (in g mL-1) of a 3.60 M sulphuric acid solution that is 29% H2SO4 (molar mass = 98 g mol-1) by mass will be
AIEEE 2007
105
In the reaction

2Al(s) + 6HCl(aq) $$\to$$ 2Al3+ (aq) + 6Cl-(aq) + 3H2(g)
AIEEE 2007
106
How many moles of magnesium phosphate Mg3(PO4)2 will contain 0.25 mole of oxygen atoms?
AIEEE 2006
107
Density of a 2.05M solution of acetic acid in water is 1.02 g/mL The molality of the solution is
AIEEE 2006
108
If we consider that 1/6, in place of 1/12, mass of carbon atom is taken to be the relative atomic mass unit, the mass of one mole of the substance will
AIEEE 2005
109
Two solutions of a substance (non electrolyte) are mixed in the following manner. 480 ml of 1.5 M first solution + 520 ml of 1.2 M second solution. What is the molarity of the final mixture?
AIEEE 2005
110
The ammonia evolved from the treatment of 0.30 g of an organic compound for the estimation of nitrogen was passed in 100 mL of 0.1 M sulphuric acid. The excess of acid required 20 mL of 0.5 M sodium hydroxide solution for complete neutralization. The organic compound is
AIEEE 2004
111
6.02 $$\times$$ 1020 molecules of urea are present in 100 ml of its solution. The concentration of urea solution is
(Avogadro constant, NA = 6.02 $$\times$$ 1023 mol-1)
AIEEE 2004
112
To neutralise completely 20 mL of 0.1 M aqueous solution of phosphorous acid (H3PO3), the volume of 0.1 M aqueous KOH solution required is
AIEEE 2004
113
What volume of hydrogen gas at 273 K and 1 atm pressure will be consumed in obtaining 21.6 g of elemental boron (atomic mass = 10.8) from the reduction of boron trichloride by hydrogen?
AIEEE 2003
114
25 ml of a solution of barium hydroxide on titration with a 0.1 molar solution of hydrochloric acid gave a litre value of 35 ml. The molarity of barium hydroxide solution was
AIEEE 2003
115
Number of atoms in 558.5 gram Fe (at. wt. of Fe = 55.85 g mol-1) is
AIEEE 2002
116
With increase of temperature, which of these changes?
AIEEE 2002
117
In a compound C, H and N atoms are present in 9 : 1 : 3.5 by weight . Molecular weight of the compound is 108 g mol-1 . Molecular formula of compound is
AIEEE 2002

Numerical

1

0.25 g of an organic compound "A" containing carbon, hydrogen and oxygen was analysed using the combustion method. There was an increase in mass of $\mathrm{CaCl}_2$ tube and potash tube at the end of the experiment. The amount was found to be 0.15 g and 0.1837 g , respectively. The percentage of oxygen in compound A is

$\_\_\_\_$ %. (Nearest integer)

(Given: molar mass in $\mathrm{g} \mathrm{mol}^{-1} \mathrm{H}: 1, \mathrm{C}: 12, \mathrm{O}: 16$ )

JEE Main 2026 (Online) 24th January Evening Shift
2

$x $ $\mathrm{mg}$ of pure HCl was used to make an aqueous solution. 25.0 mL of $0.1 \mathrm{M} \mathrm{Ba}(\mathrm{OH})_2$ solution is used when the HCl solution was titrated against it. The numerical value of $x$ is $\_\_\_\_$ $\times 10^{-1}$. (Nearest integer)

Given : Molar mass of HCl and $\mathrm{Ba}(\mathrm{OH})_2$ are 36.5 and $171.0 \mathrm{~g} \mathrm{~mol}^{-1}$ respectively.

JEE Main 2026 (Online) 23rd January Morning Shift
3

20 mL of sodium iodide solution gave 4.74 g silver iodide when treated with excess of silver nitrate solution. The molarity of the sodium iodide solution is _______ M. (Nearest Integer value)

(Given : Na = 23, I = 127, Ag = 108, N = 14, O = 16 g mol-1)

JEE Main 2025 (Online) 8th April Evening Shift
4

Butane reacts with oxygen to produce carbon dioxide and water following the equation given below.

$$ \mathrm{C}_4 \mathrm{H}_{10}(\mathrm{~g})+\frac{13}{2} \mathrm{O}_2(\mathrm{~g}) \rightarrow 4 \mathrm{CO}_2(\mathrm{~g})+5 \mathrm{H}_2 \mathrm{O}(\mathrm{l}) $$

If 174.0 kg of butane is mixed with 320.0 kg of $\mathrm{O}_2$, the volume of water formed in liters is

_____________. (Nearest integer)

[Given : (a) Molar mass of C, H, O are $12,1,16 \mathrm{~g} \mathrm{~mol}^{-1}$ respectively, (b) Density of water $\left.=1 \mathrm{~g} \mathrm{~mL}^{-1}\right]$

JEE Main 2025 (Online) 7th April Evening Shift
5

An organic compound weighing 500 mg , produced 220 mg of $\mathrm{CO}_2$, on complete combustion. The percentage composition of carbon in the compound is _________ $\%$. (nearest integer)

(Given molar mass in $\mathrm{g} \mathrm{mol}^{-1}$ of $\mathrm{C}: 12, \mathrm{O}: 16$ )

JEE Main 2025 (Online) 7th April Morning Shift
6

Thyroxine, the hormone has given below structure

JEE Main 2025 (Online) 7th April Morning Shift Chemistry - Some Basic Concepts of Chemistry Question 30 English

The percentage of iodine in thyroxine is __________ %. (nearest integer)

(Given molar mass in $\mathrm{g} \mathrm{mol}^{-1} \mathrm{C}: 12, \mathrm{H}: 1, \mathrm{O}: 16, \mathrm{~N}: 14, \mathrm{I}: 127$ )

JEE Main 2025 (Online) 7th April Morning Shift
7

The amount of calcium oxide produced on heating 150 kg limestone ( $75 \%$ pure) is _________ kg. (Nearest integer)

Given: Molar mass (in $\mathrm{g} \mathrm{mol}^{-1}$ ) of Ca-40, O-16, C-12

JEE Main 2025 (Online) 4th April Evening Shift
8

Fortification of food with iron is done using $\mathrm{FeSO}_4 \cdot 7 \mathrm{H}_2 \mathrm{O}$. The mass in grams of the $\mathrm{FeSO}_4$. $7 \mathrm{H}_2 \mathrm{O}$ required to achieve 12 ppm of iron in 150 kg of wheat is ______ (Nearest integer)

[Given: Molar mass of $\mathrm{Fe}, \mathrm{S}$ and and O respectively are 56, 32 and $16 \mathrm{~g} \mathrm{~mol}^{-1}$ ]

JEE Main 2025 (Online) 4th April Morning Shift
9

X g of nitrobenzene on nitration gave 4.2 g of m -dinitrobenzene. X = __________g. (nearest integer)

[Given : molar mass (in $\left.\left.\mathrm{g} \mathrm{mol}^{-1}\right) \mathrm{C}: 12, \mathrm{H}: 1, \mathrm{O}: 16, \mathrm{~N}: 14\right]$

JEE Main 2025 (Online) 3rd April Evening Shift
10

$$ \text {During estimation of nitrogen by Dumas' method of compound } \mathrm{X}(0.42 \mathrm{~g}) $$

JEE Main 2025 (Online) 3rd April Morning Shift Chemistry - Some Basic Concepts of Chemistry Question 27 English

_________mL of $\mathrm{N}_2$ gas will be liberated at STP. (nearest integer)

(Given molar mass in $\mathrm{g}~ \mathrm{mol}^{-1}: \mathrm{C}: 12, \mathrm{H}: 1, \mathrm{~N}: 14$ )

JEE Main 2025 (Online) 3rd April Morning Shift
11

0.5 g of an organic compound on combustion gave 1.46 g of $\mathrm{CO}_2$ and 0.9 g of $\mathrm{H}_2 \mathrm{O}$. The percentage of carbon in the compound is _______________. (Nearest integer)

[Given : Molar mass (in $\left.\mathrm{g} \mathrm{mol}^{-1}\right) \mathrm{C}: 12, \mathrm{H}: 1, \mathrm{O}: 16$ ]

JEE Main 2025 (Online) 3rd April Morning Shift
12

The molarity of a $70 \%$ (mass/mass) aqueous solution of a monobasic acid (X) is _________ $\times 10^{-1}$ M (Nearest integer)

[Given: Density of aqueous solution of (X) is $1.25 \mathrm{~g} \mathrm{~mL}^{-1}$

Molar mass of the acid is $70 \mathrm{~g} \mathrm{~mol}^{-1}$ ]

JEE Main 2025 (Online) 28th January Morning Shift
13

Quantitative analysis of an organic compound (X) shows following % composition.

C : $14.5 \%$

Cl : 64.46%

H: 1.8 %

(Empirical formula mass of the compound $(\mathrm{X})$ is _________ $\times 10^{-1}$

(Given molar mass in $\mathrm{g} \mathrm{~mol}^{-1}$ of $\mathrm{C}: 12, \mathrm{H}: 1, \mathrm{O}: 16, \mathrm{Cl}: 35.5$)

JEE Main 2025 (Online) 28th January Morning Shift
14

Consider the following reaction occurring in the blast furnace:

$$\mathrm{Fe}_3 \mathrm{O}_{4(\mathrm{~s})}+4 \mathrm{CO}_{(\mathrm{g})} \rightarrow 3 \mathrm{Fe}_{(\mathrm{l})}+4 \mathrm{CO}_{2(\mathrm{~g})}$$

' $x$ ' kg of iron is produced when $2.32 \times 10^3 \mathrm{~kg} \mathrm{Fe}_3 \mathrm{O}_4$ and $2.8 \times 10^2 \mathrm{~kg} \mathrm{CO}$ are brought together in the furnace. The value of ' $x$ ' is _________ . (nearest integer)

{Given: molar mass of $\mathrm{Fe}_3 \mathrm{O}_4=232 \mathrm{~g} \mathrm{~mol}^{-1}$

molar mass of $\mathrm{CO}=28 \mathrm{~g} \mathrm{~mol}^{-1}$

molar mass of $\mathrm{Fe}=56 \mathrm{~g} \mathrm{~mol}^{-1}$}

JEE Main 2025 (Online) 24th January Morning Shift
15

Xg of benzoic acid on reaction with aq $\mathrm{NaHCO}_3$ released $\mathrm{CO}_2$ that occupied 11.2 L volume at STP.

X is _________ g.

JEE Main 2025 (Online) 24th January Morning Shift
16

0.01 mole of an organic compound $(X)$ containing $10 \%$ hydrogen, on complete combustion produced $0.9 \mathrm{~g} \mathrm{H}_2 \mathrm{O}$. Molar mass of $(\mathrm{X})$ is _________ $\mathrm{g} \mathrm{~mol}^{-1}$.

JEE Main 2025 (Online) 23rd January Evening Shift
17

When 81.0 g of aluminium is allowed to react with 128.0 g of oxygen gas, the mass of aluminium oxide produced in grams is ________ . (Nearest integer)

Given :

Molar mass of Al is $27.0 \mathrm{~g} \mathrm{~mol}^{-1}$

Molar mass of O is $16.0 \mathrm{~g} \mathrm{~mol}^{-1}$

JEE Main 2025 (Online) 23rd January Evening Shift
18

During " S " estimation, 160 mg of an organic compound gives 466 mg of barium sulphate. The percentage of Sulphur in the given compound is _________ %.

(Given molar mass in $\mathrm{g} \mathrm{~mol}^{-1}$ of $\mathrm{Ba}: 137, \mathrm{~S}: 32, {\mathrm{O}: 16}$)

JEE Main 2025 (Online) 23rd January Morning Shift
19

20 mL of 2 M NaOH solution is added to 400 mL of 0.5 M NaOH solution. The final concentration of the solution is _________ $\times 10^{-2} \mathrm{M}$. (Nearest integer)

JEE Main 2025 (Online) 22nd January Evening Shift
20

Molarity $$(\mathrm{M})$$ of an aqueous solution containing $$x \mathrm{~g}$$ of anhyd. $$\mathrm{CuSO}_4$$ in $$500 \mathrm{~mL}$$ solution at $$32^{\circ} \mathrm{C}$$ is $$2 \times 10^{-1} \mathrm{M}$$. Its molality will be _________ $$\times 10^{-3} \mathrm{~m}$$. (nearest integer). [Given density of the solution $$=1.25 \mathrm{~g} / \mathrm{mL}$$]

JEE Main 2024 (Online) 9th April Morning Shift
21

A solution is prepared by adding 1 mole ethyl alcohol in 9 mole water. The mass percent of solute in the solution is ________ (Integer answer) (Given : Molar mass in $$\mathrm{g} \mathrm{~mol}^{-1}$$ Ethyl alcohol : 46 water : 18)

JEE Main 2024 (Online) 8th April Evening Shift
22

Molality of an aqueous solution of urea is $$4.44 \mathrm{~m}$$. Mole fraction of urea in solution is $$x \times 10^{-3}$$, Value of $$x$$ is ________. (Integer answer)

JEE Main 2024 (Online) 8th April Evening Shift
23

From $$6.55 \mathrm{~g}$$ of aniline, the maximum amount of acetanilide that can be prepared will be ________ $$\times 10^{-1} \mathrm{~g}$$.

JEE Main 2024 (Online) 4th April Evening Shift
24

$$\mathrm{Xg}$$ of ethylamine is subjected to reaction with $$\mathrm{NaNO}_2 / \mathrm{HCl}$$ followed by water; evolved dinitrogen gas which occupied $$2.24 \mathrm{~L}$$ volume at STP. X is _________ $$\times 10^{-1} \mathrm{~g}$$.

JEE Main 2024 (Online) 4th April Morning Shift
25
$10 \mathrm{~mL}$ of gaseous hydrocarbon on combustion gives $40 \mathrm{~mL}$ of $\mathrm{CO}_2(\mathrm{~g})$ and $50 \mathrm{~mL}$ of water vapour. Total number of carbon and hydrogen atoms in the hydrocarbon is _________ .
JEE Main 2024 (Online) 1st February Evening Shift
26
Consider the following reaction :

$$ 3 \mathrm{PbCl}_2+2\left(\mathrm{NH}_4\right)_3 \mathrm{PO}_4 \rightarrow \mathrm{Pb}_3\left(\mathrm{PO}_4\right)_2+6 \mathrm{NH}_4 \mathrm{Cl} $$

If $72 ~\mathrm{mmol}$ of $\mathrm{PbCl}_2$ is mixed with $50 ~\mathrm{mmol}$ of $\left(\mathrm{NH}_4\right)_3 \mathrm{PO}_4$, then the amount of $\mathrm{Pb}_3\left(\mathrm{PO}_4\right)_2$ formed is ________ mmol (nearest integer).
JEE Main 2024 (Online) 1st February Morning Shift
27

The molarity of $$1 \mathrm{~L}$$ orthophosphoric acid $$\left(\mathrm{H}_3 \mathrm{PO}_4\right)$$ having $$70 \%$$ purity by weight (specific gravity $$1.54 \mathrm{~g} \mathrm{~cm}^{-3}$$) is __________ $$\mathrm{M}$$.

(Molar mass of $$\mathrm{H}_3 \mathrm{PO}_4=98 \mathrm{~g} \mathrm{~mol}^{-1}$$)

JEE Main 2024 (Online) 31st January Evening Shift
28

Number of moles of methane required to produce $$22 \mathrm{~g} \mathrm{~CO}_{2(\mathrm{~g})}$$ after combustion is $$\mathrm{x} \times 10^{-2}$$ moles. The value of $$\mathrm{x}$$ is _________.

JEE Main 2024 (Online) 31st January Morning Shift
29

Molar mass of the salt from $$\mathrm{NaBr}, \mathrm{NaNO}_3, \mathrm{KI}$$ and $$\mathrm{CaF}_2$$ which does not evolve coloured vapours on heating with concentrated $$\mathrm{H}_2 \mathrm{SO}_4$$ is ________ $$\mathrm{g} \mathrm{~mol}{ }^{-1}$$.

(Molar mass in $$\mathrm{g} \mathrm{~mol}^{-1}: \mathrm{Na}: 23, \mathrm{~N}: 14, \mathrm{~K}: 39, \mathrm{O}: 16, \mathrm{Br}: 80, \mathrm{I}: 127, \mathrm{~F}: 19, \mathrm{Ca}: 40)$$

JEE Main 2024 (Online) 31st January Morning Shift
30

The mass of sodium acetate $$\left(\mathrm{CH}_3 \mathrm{COONa}\right)$$ required to prepare $$250 \mathrm{~mL}$$ of $$0.35 \mathrm{~M}$$ aqueous solution is ________ g. (Molar mass of $$\mathrm{CH}_3 \mathrm{COONa}$$ is $$82.02 \mathrm{~g} \mathrm{~mol}^{-1}$$)

JEE Main 2024 (Online) 30th January Morning Shift
31

$$0.05 \mathrm{~cm}$$ thick coating of silver is deposited on a plate of $$0.05 \mathrm{~m}^2$$ area. The number of silver atoms deposited on plate are ________ $$\times 10^{23}$$. (At mass $$\mathrm{Ag}=108, \mathrm{~d}=7.9 \mathrm{~g} \mathrm{~cm}^{-3}$$)

JEE Main 2024 (Online) 30th January Morning Shift
32

If $$50 \mathrm{~mL}$$ of $$0.5 \mathrm{M}$$ oxalic acid is required to neutralise $$25 \mathrm{~mL}$$ of $$\mathrm{NaOH}$$ solution, the amount of $$\mathrm{NaOH}$$ in $$50 \mathrm{~mL}$$ of given $$\mathrm{NaOH}$$ solution is ______ g.

JEE Main 2024 (Online) 29th January Evening Shift
33

Molality of 0.8 M H$$_2$$SO$$_4$$ solution (density 1.06 g cm$$^{-3}$$) is ________ $$\times10^{-3}$$ m.

JEE Main 2024 (Online) 29th January Evening Shift
34

A solution of $$\mathrm{H}_2 \mathrm{SO}_4$$ is $$31.4 \% \mathrm{H}_2 \mathrm{SO}_4$$ by mass and has a density of $$1.25 \mathrm{~g} / \mathrm{mL}$$. The molarity of the $$\mathrm{H}_2 \mathrm{SO}_4$$ solution is _________ $$\mathrm{M}$$ (nearest integer)

[Given molar mass of $$\mathrm{H}_2 \mathrm{SO}_4=98 \mathrm{~g} \mathrm{~mol}^{-1}$$]

JEE Main 2024 (Online) 29th January Morning Shift
35

$$9.3 \mathrm{~g}$$ of aniline is subjected to reaction with excess of acetic anhydride to prepare acetanilide. The mass of acetanilide produced if the reaction is $$100 \%$$ completed is _________ $$\times 10^{-1} \mathrm{~g}$$.

(Given molar mass in $$\mathrm{g} \mathrm{~mol}^{-1}$$

$$\begin{aligned} & \mathrm{N}: 14, \mathrm{O}: 16, \\ & \mathrm{C}: 12, \mathrm{H}: 1 \text { ) } \end{aligned}$$

JEE Main 2024 (Online) 27th January Evening Shift
36

Volume of $$3 \mathrm{M} \mathrm{~NaOH}$$ (formula weight $$40 \mathrm{~g} \mathrm{~mol}^{-1}$$ ) which can be prepared from $$84 \mathrm{~g}$$ of $$\mathrm{NaOH}$$ is __________ $$\times 10^{-1} \mathrm{dm}^3$$.

JEE Main 2024 (Online) 27th January Evening Shift
37

Mass of methane required to produce $$22 \mathrm{~g}$$ of $$\mathrm{CO}_2$$ after complete combustion is _______ g.

(Given Molar mass in g mol-1 $$\mathrm{C}=12.0$$, $$\mathrm{H}=1.0$$, $$\mathrm{O}=16.0)$$

JEE Main 2024 (Online) 27th January Morning Shift
38
The volume (in $\mathrm{mL}$) of $0.1 \mathrm{M} ~\mathrm{AgNO}_{3}$ required for complete precipitation of chloride ions present in $20 \mathrm{~mL}$ of $0.01 \mathrm{M}$ solution of $\left[\mathrm{Cr}\left(\mathrm{H}_{2} \mathrm{O}\right)_{5} \mathrm{Cl}\right] \mathrm{Cl}_{2}$ as silver chloride is __________.
JEE Main 2023 (Online) 15th April Morning Shift
39

$$1 \mathrm{~g}$$ of a carbonate $$\left(\mathrm{M}_{2} \mathrm{CO}_{3}\right)$$ on treatment with excess $$\mathrm{HCl}$$ produces $$0.01 \mathrm{~mol}$$ of $$\mathrm{CO}_{2}$$. The molar mass of $$\mathrm{M}_{2} \mathrm{CO}_{3}$$ is __________ $$\mathrm{g} ~\mathrm{mol}^{-1}$$. (Nearest integer)

JEE Main 2023 (Online) 13th April Evening Shift
40

An organic compound gives $$0.220 \mathrm{~g}$$ of $$\mathrm{CO}_{2}$$ and $$0.126 \mathrm{~g}$$ of $$\mathrm{H}_{2} \mathrm{O}$$ on complete combustion. If the $$\%$$ of carbon is 24 then the $$\%$$ of hydrogen is __________ $$\times 10^{-1}$$. ( Nearest integer)

JEE Main 2023 (Online) 13th April Morning Shift
41

$$20 \mathrm{~mL}$$ of calcium hydroxide was consumed when it was reacted with $$10 \mathrm{~mL}$$ of unknown solution of $$\mathrm{H}_{2} \mathrm{SO}_{4}$$. Also $$20 \mathrm{~mL}$$ standard solution of $$0.5 ~\mathrm{M} ~\mathrm{HCl}$$ containing 2 drops of phenolphthalein was titrated with calcium hydroxide, the mixture showed pink colour when burette displayed the value of $$35.5 \mathrm{~mL}$$ whereas the burette showed $$25.5 \mathrm{~mL}$$ initially. The concentration of $$\mathrm{H}_{2} \mathrm{SO}_{4}$$ is _____________ M. (Nearest integer)

JEE Main 2023 (Online) 13th April Morning Shift
42

The volume of hydrogen liberated at STP by treating $$2.4 \mathrm{~g}$$ of magnesium with excess of hydrochloric acid is _________ $$\times ~10^{-2} \mathrm{~L}$$

Given : Molar volume of gas is $$22.4 \mathrm{~L}$$ at STP.

Molar mass of magnesium is $$24 \mathrm{~g} \mathrm{~mol}^{-1}$$

JEE Main 2023 (Online) 11th April Evening Shift
43

A solution of sugar is obtained by mixing $$200 \mathrm{~g}$$ of its $$25 \%$$ solution and $$500 \mathrm{~g}$$ of its $$40 \%$$ solution (both by mass). The mass percentage of the resulting sugar solution is ___________ (Nearest integer)

JEE Main 2023 (Online) 11th April Morning Shift
44

$$0.5 \mathrm{~g}$$ of an organic compound $$(\mathrm{X})$$ with $$60 \%$$ carbon will produce __________ $$\times 10^{-1} \mathrm{~g}$$ of $$\mathrm{CO}_{2}$$ on complete combustion.

JEE Main 2023 (Online) 8th April Morning Shift
45

If 5 moles of $$\mathrm{BaCl}_{2}$$ is mixed with 2 moles of $$\mathrm{Na}_{3} \mathrm{PO}_{4}$$, the maximum number of moles of $$\mathrm{Ba}_{3}\left(\mathrm{PO}_{4}\right)_{2}$$ formed is ___________ (Nearest integer)

JEE Main 2023 (Online) 6th April Morning Shift
46

The molality of a $$10 \%(\mathrm{v} / \mathrm{v})$$ solution of di-bromine solution in $$\mathrm{CCl}_{4}$$ (carbon tetrachloride) is '$$x$$'. $$x=$$ ____________ $$\times 10^{-2} ~\mathrm{M}$$. (Nearest integer)

[Given : molar mass of $$\mathrm{Br}_{2}=160 \mathrm{~g} \mathrm{~mol}^{-1}$$

atomic mass of $$\mathrm{C}=12 \mathrm{~g} \mathrm{~mol}^{-1}$$

atomic mass of $$\mathrm{Cl}=35.5 \mathrm{~g} \mathrm{~mol}^{-1}$$

density of dibromine $$=3.2 \mathrm{~g} \mathrm{~cm}^{-3}$$

density of $$\mathrm{CCl}_{4}=1.6 \mathrm{~g} \mathrm{~cm}^{-3}$$]

JEE Main 2023 (Online) 1st February Evening Shift
47

The density of $$3 \mathrm{M}$$ solution of $$\mathrm{NaCl}$$ is $$1.0 \mathrm{~g} \mathrm{~mL}^{-1}$$. Molality of the solution is ____________ $$\times 10^{-2} \mathrm{~m}$$. (Nearest integer).

Given: Molar mass of $$\mathrm{Na}$$ and $$\mathrm{Cl}$$ is $$23$$ and $$35.5 \mathrm{~g} \mathrm{~mol}^{-1}$$ respectively.

JEE Main 2023 (Online) 1st February Morning Shift
48
Assume carbon burns according to the following equation :

$2 \mathrm{C}_{(\mathrm{s})}+\mathrm{O}_{2(\mathrm{~g})} \rightarrow 2 \mathrm{CO}(\mathrm{g})$

when $12 \mathrm{~g}$ carbon is burnt in $48 \mathrm{~g}$ of oxygen, the volume of carbon monoxide produced is ___________ $\times 10^{-1} \mathrm{~L}$ at STP [nearest integer]

[Given: Assume $\mathrm{CO}$ as ideal gas, Mass of $\mathrm{C}$ is $12 \mathrm{~g} \mathrm{~mol}^{-1}$, Mass of $\mathrm{O}$ is $16 \mathrm{~g} \mathrm{~mol}^{-1}$ and molar volume of an ideal gas at STP is $22.7 \mathrm{~L} \mathrm{~mol}^{-1}$ ]
JEE Main 2023 (Online) 31st January Evening Shift
49
A sample of a metal oxide has formula $\mathrm{M}_{0.83} \mathrm{O}_{1.00}$. The metal $\mathrm{M}$ can exist in two oxidation states $+2$ and $+3$.

In the sample of $\mathrm{M}_{0.83} \mathrm{O}_{1.00}$, the percentage of metal ions existing in $+2$ oxidation state is __________ $\%$. (nearest integer)
JEE Main 2023 (Online) 31st January Evening Shift
50

Zinc reacts with hydrochloric acid to give hydrogen and zinc chloride. The volume of hydrogen gas produced at STP from the reaction of $$11.5 \mathrm{~g}$$ of zinc with excess $$\mathrm{HCl}$$ is __________ L (Nearest integer)

(Given : Molar mass of $$\mathrm{Zn}$$ is $$65.4 \mathrm{~g} \mathrm{~mol}^{-1}$$ and Molar volume of $$\mathrm{H}_{2}$$ at $$\mathrm{STP}=22.7 \mathrm{~L}$$ )

JEE Main 2023 (Online) 31st January Morning Shift
51

On complete combustion, $$0.492 \mathrm{~g}$$ of an organic compound gave $$0.792 \mathrm{~g}$$ of $$\mathrm{CO}_{2}$$. The % of carbon in the organic compound is ___________ (Nearest integer)

JEE Main 2023 (Online) 31st January Morning Shift
52

The strength of 50 volume solution of hydrogen peroxide is ______ $\mathrm{g} / \mathrm{L}$ (Nearest integer).

Given:

Molar mass of $\mathrm{H}_{2} \mathrm{O}_{2}$ is $34 \mathrm{~g} \mathrm{~mol}^{-1}$

Molar volume of gas at $\mathrm{STP}=22.7 \mathrm{~L}$
JEE Main 2023 (Online) 30th January Evening Shift
53

Some amount of dichloromethane $$\left(\mathrm{CH}_{2} \mathrm{Cl}_{2}\right)$$ is added to $$671.141 \mathrm{~mL}$$ of chloroform $$\left(\mathrm{CHCl}_{3}\right)$$ to prepare $$2.6 \times 10^{-3} \mathrm{M}$$ solution of $$\mathrm{CH}_{2} \mathrm{Cl}_{2}(\mathrm{DCM})$$. The concentration of $$\mathrm{DCM}$$ is ___________ ppm (by mass).

Given :

atomic mass : C = 12

H = 1

Cl = 35.5

density of $$\mathrm{CHCl}_{3}=1.49 \mathrm{~g} \mathrm{~cm}^{-3}$$

JEE Main 2023 (Online) 30th January Morning Shift
54

The volume of HCl, containing 73 g L$$^{-1}$$, required to completely neutralise NaOH obtained by reacting 0.69 g of metallic sodium with water, is __________ mL. (Nearest Integer)

(Given : molar masses of Na, Cl, O, H, are 23, 35.5, 16 and 1 g mol$$^{-1}$$ respectively.)

JEE Main 2023 (Online) 29th January Evening Shift
55

When 0.01 mol of an organic compound containing 60% carbon was burnt completely, 4.4 g of CO$$_2$$ was produced. The molar mass of compound is _____________ g mol$$^{-1}$$ (Nearest integer).

JEE Main 2023 (Online) 29th January Evening Shift
56

Number of hydrogen atoms per molecule of a hydrocarbon A having 85.8% carbon is __________

(Given : Molar mass of A = 84 g mol$$^{-1}$$)

JEE Main 2023 (Online) 25th January Evening Shift
57

In sulphur estimation, 0.471 g of an organic compound gave 1.4439 g of barium sulphate. The percentage of sulphur in the compound is ____________ (Nearest Integer)

(Given : Atomic mass Ba: 137 u, S: 32 u, O: 16 u)

JEE Main 2023 (Online) 25th January Morning Shift
58

The number of units, which are used to express concentration of solutions from the following is _________

Mass percent, Mole, Mole fraction, Molarity, ppm, Molality

JEE Main 2023 (Online) 24th January Evening Shift
59

When $$\mathrm{Fe_{0.93}O}$$ is heated in presence of oxygen, it converts to $$\mathrm{Fe_2O_3}$$. The number of correct statement/s from the following is ________

A. The equivalent weight of $$\mathrm{Fe_{0.93}O}$$ is $${{\mathrm{Molecular\,weight}} \over {0.79}}$$

B. The number of moles of Fe$$^{2+}$$ and Fe$$^{3+}$$ in 1 mole of $$\mathrm{Fe_{0.93}O}$$ is 0.79 and 0.14 respectively

C. $$\mathrm{Fe_{0.93}O}$$ is metal deficient with lattice comprising of cubic closed packed arrangement of O$$^{2-}$$ ions

D. The % composition of Fe$$^{2+}$$ and Fe$$^{3+}$$ in $$\mathrm{Fe_{0.93}O}$$ is 85% and 15% respectively

JEE Main 2023 (Online) 24th January Morning Shift
60

5 g of NaOH was dissolved in deionized water to prepare a 450 mL stock solution. What volume (in mL) of this solution would be required to prepare 500 mL of 0.1 M solution? _____________

Given : Molar Mass of Na, O and H is 23, 16 and 1 g mol$$^{-1}$$ respectively

JEE Main 2023 (Online) 24th January Morning Shift
61

A 1.84 mg sample of polyhydric alcoholic compound 'X' of molar mass 92.0 g/mol gave 1.344 mL of $$\mathrm{H}_{2}$$ gas at STP. The number of alcoholic hydrogens present in compound 'X' is ________.

JEE Main 2022 (Online) 29th July Evening Shift
62

2L of 0.2M H2SO4 is reacted with 2L of 0.1M NaOH solution, the molarity of the resulting product Na2SO4 in the solution is _________ millimolar. (Nearest integer)

JEE Main 2022 (Online) 28th July Evening Shift
63

In the given reaction,

$$X+Y+3 Z \leftrightarrows X YZ_{3}$$

if one mole of each of $$X$$ and $$Y$$ with $$0.05 \mathrm{~mol}$$ of $$Z$$ gives compound $$X Y Z_{3}$$. (Given : Atomic masses of $$X, Y$$ and $$Z$$ are 10, 20 and 30 amu, respectively.) The yield of $$X YZ_{3}$$ is _____________ g. (Nearest integer)

JEE Main 2022 (Online) 28th July Morning Shift
64

On complete combustion of $$0.492 \mathrm{~g}$$ of an organic compound containing $$\mathrm{C}, \mathrm{H}$$ and $$\mathrm{O}$$, $$0.7938 \mathrm{~g}$$ of $$\mathrm{CO}_{2}$$ and $$0.4428 \mathrm{~g}$$ of $$\mathrm{H}_{2} \mathrm{O}$$ was produced. The % composition of oxygen in the compound is ___________.

JEE Main 2022 (Online) 28th July Morning Shift
65

$$20 \mathrm{~mL}$$ of $$0.02 \,\mathrm{M} \,\mathrm{K}_{2} \mathrm{Cr}_{2} \mathrm{O}_{7}$$ solution is used for the titration of $$10 \mathrm{~mL}$$ of $$\mathrm{Fe}^{2+}$$ solution in the acidic medium.

The molarity of $$\mathrm{Fe}^{2+}$$ solution is __________ $$\times \,10^{-2}\, \mathrm{M}$$. (Nearest Integer)

JEE Main 2022 (Online) 27th July Morning Shift
66

A $$100 \mathrm{~mL}$$ solution of $$\mathrm{CH}_{3} \mathrm{CH}_{2} \mathrm{MgBr}$$ on treatment with methanol produces $$2.24 \mathrm{~mL}$$ of a gas at STP. The weight of gas produced is _____________ mg. [nearest integer]

JEE Main 2022 (Online) 26th July Evening Shift
67

Chlorophyll extracted from the crushed green leaves was dissolved in water to make $$2 \mathrm{~L}$$ solution of Mg of concentration $$48\, \mathrm{ppm}$$. The number of atoms of $$\mathrm{Mg}$$ in this solution is $$x \times 10^{20}$$ atoms. The value of $$x$$ is ___________. (Nearest Integer)

(Given : Atomic mass of $$\mathrm{Mg}$$ is $$24 \mathrm{~g} \mathrm{~mol}^{-1} ; \mathrm{N}_{\mathrm{A}}=6.02 \times 10^{23} \mathrm{~mol}^{-1}$$ )

JEE Main 2022 (Online) 26th July Morning Shift
68

When 800 mL of 0.5 M nitric acid is heated in a beaker, its volume is reduced to half and 11.5 g of nitric acid is evaporated. The molarity of the remaining nitric acid solution is x $$\times$$ 10$$-$$2 M. (Nearest integer)

(Molar mass of nitric acid is 63 g mol$$-$$1)

JEE Main 2022 (Online) 26th July Morning Shift
69

56.0 L of nitrogen gas is mixed with excess hydrogen gas and it is found that 20 L of ammonia gas is produced. The volume of unused nitrogen gas is found to be _________ L.

JEE Main 2022 (Online) 25th July Evening Shift
70

A sample of 4.5 mg of an unknown monohydric alcohol, R-OH was added to methylmagnesium iodide. A gas is evolved and is collected and its volume measured to be 3.1 mL. The molecular weight of the unknown alcohol is __________ g/mol. [Nearest integer]

JEE Main 2022 (Online) 25th July Evening Shift
71

Blister copper is produced by reaction of copper oxide with copper sulphide.

2Cu2O + Cu2S $$\to$$ 6Cu + SO2

When 2.86 $$\times$$ 103 g of Cu2O and 4.77 $$\times$$ 103 g of Cu2S are used for reaction, the mass of copper produced is _____________ g. (nearest integer)

(Atomic mass of Cu = 63.5 a.m. u, S = 32.0 a.m. u, O = 16.0 a.m. u)

JEE Main 2022 (Online) 30th June Morning Shift
72

The complete combustion of 0.492 g of an organic compound containing 'C', 'H' and 'O' gives 0.793 g of CO2 and 0.442 g of H2O. The percentage of oxygen composition in the organic compound is ______________. (nearest integer)

JEE Main 2022 (Online) 28th June Evening Shift
73

116 g of a substance upon dissociation reaction, yields 7.5 g of hydrogen, 60 g of oxygen and 48.5 g of carbon. Given that the atomic masses of H, O and C are 1, 16 and 12, respectively. The data agrees with how many formulae of the following?

A. CH3COOH, B. HCHO, C. CH3OOCH3, D. CH3CHO

JEE Main 2022 (Online) 27th June Evening Shift
74

Two elements A and B which form 0.15 moles of A2B and AB3 type compounds. If both A2B and AB3 weigh equally, then the atomic weight of A is _____________ times of atomic weight of B.

JEE Main 2022 (Online) 27th June Morning Shift
75

CNG is an important transportation fuel. When 100 g CNG is mixed with 208 g oxygen in vehicles, it leads to the formation of CO2 and H2O and produces large quantity of heat during this combustion, then the amount of carbon dioxide, produced in grams is ____________. [nearest integer]

[Assume CNG to be methane]

JEE Main 2022 (Online) 26th June Evening Shift
76

The moles of methane required to produce 81 g of water after complete combustion is _____________ $$\times$$ 10$$-$$2 mol. [nearest integer]

JEE Main 2022 (Online) 26th June Evening Shift
77

On complete combustion 0.30 g of an organic compound gave 0.20 g of carbon dioxide and 0.10 g of water. The percentage of carbon in the given organic compound is _____________. (Nearest integer)

JEE Main 2022 (Online) 26th June Morning Shift
78

A protein 'A' contains 0.30% of glycine (molecular weight 75). The minimum molar mass of the protein 'A' is __________ $$\times$$ 103 g mol$$-$$1 [nearest integer]

JEE Main 2022 (Online) 25th June Evening Shift
79

The number of N atoms in 681 g of C7H5N3O6 is x $$\times$$ 1021. The value of x is (NA = 6.02 $$\times$$ 1023 mol$$-$$1) (Nearest Integer)

JEE Main 2022 (Online) 25th June Morning Shift
80

1 L aqueous solution of H2SO4 contains 0.02 m mol H2SO4. 50% of this solution is diluted with deionized water to give 1 L solution (A). In solution (A), 0.01 m mol of H2SO4 are added. Total m mols of H2SO4 in the final solution is ___________ $$\times$$ 103 m mols.

JEE Main 2022 (Online) 25th June Morning Shift
81

Number of grams of bromine that will completely react with 5.0 g of pent-1-ene is ___________ $$\times$$ 10$$-$$2 g. (Atomic mass of Br = 80 g/mol) [Nearest Integer]

JEE Main 2022 (Online) 25th June Morning Shift
82

A 0.166 g sample of an organic compound was digested with conc. H2SO4 and then distilled with NaOH. The ammonia gas evolved was passed through 50.0 mL of 0.5 N H2SO4. The used acid required 30.0 mL of 0.25 N NaOH for complete neutralization. The mass percentage of nitrogen in the organic compound is ____________.

JEE Main 2022 (Online) 24th June Morning Shift
83
The number of atoms in 8g of sodium is x $$\times$$ 1023. The value of x is ____________. (Nearest integer)

[Given : NA = 6.02 $$\times$$ 1023 mol$$-$$1

Atomic mass of Na = 23.0 u]
JEE Main 2021 (Online) 1st September Evening Shift
84
If 80 g of copper sulphate CuSO4 . 5H2O is dissolved in deionised water to make 5L of solution. The concentration of the copper sulphate solution is x $$\times$$ 10$$-$$3 mol L$$-$$1. The value of x is _____________.

[Atomic masses Cu : 63.54u, S : 32u, O : 16u, H : 1u]
JEE Main 2021 (Online) 1st September Evening Shift
85
Sodium oxide reacts with water to produce sodium hydroxide. 20.0 g of sodium oxide is dissolved in 500 mL of water. Neglecting the change in volume, the concentration of the resulting NaOH solution is ______________ $$\times$$ 10$$-$$1 M. (Nearest integer) [Atomic mass : Na = 23.0, O = 16.0, H = 1.0]
JEE Main 2021 (Online) 31st August Evening Shift
86
The molarity of the solution prepared by dissolving 6.3 g of oxalic acid (H2C2O4.2H2O) in 250 mL of water in mol L$$-$$1 is x $$\times$$ 10$$-$$2. The value of x is _____________. (Nearest integer) [Atomic mass : H : 1.0, C : 12.0, O : 16.0]
JEE Main 2021 (Online) 31st August Morning Shift
87
100 g of propane is completely reacted with 1000 g of oxygen. The mole fraction of carbon dioxide in the resulting mixture is x $$\times$$ 10$$-$$2. The value of x is ____________. (Nearest integer)

[Atomic weight : H = 1.008; C = 12.00; O = 16.00]
JEE Main 2021 (Online) 27th August Evening Shift
88
In Carius method for estimation of halogens, 0.2 g of an organic compound gave 0.188 g of AgBr. The percentage of bromine in the compound is ______________. (Nearest integer)

[Atomic mass : Ag = 108, Br = 80]
JEE Main 2021 (Online) 27th August Morning Shift
89
100 mL of Na3PO4 solution contains 3.45 g of sodium. The molarity of the solution is _____________ $$\times$$ 10$$-$$2 mol L$$-$$1. (Nearest integer)

[Atomic Masses - Na : 23.0 u, O : 16.0 u, P : 31.0 u]
JEE Main 2021 (Online) 26th August Evening Shift
90
An aqueous KCl solution of density 1.20 g mL$$-$$1 has a molality of 3.30 mol kg$$-$$1. The molarity of the solution in mol L$$-$$1 is ____________ (Nearest integer) [Molar mass of KCl = 74.5]
JEE Main 2021 (Online) 26th August Morning Shift
91
2SO2(g) + O2(g) $$\to$$ 2SO3(g)

The above reaction is carried out in a vessel starting with partial pressure PSO2 = 250 m bar, PO2 = 750 m bar and PSO3 = 0 bar. When the reaction is complete, the total pressure in the reaction vessel is _______ m bar. (Round off of the nearest integer).
JEE Main 2021 (Online) 27th July Evening Shift
92
The density of NaOH solution is 1.2 g cm$$-$$3. The molality of this solution is _____________ m. (Round off to the Nearest Integer)

[Use : Atomic mass : Na : 23.0 u, O : 16.0 u, H : 1.0 u, Density of H2O : 1.0 g cm$$-$$3]
JEE Main 2021 (Online) 27th July Morning Shift
93
The number of significant figures in 0.00340 is ____________.
JEE Main 2021 (Online) 25th July Evening Shift
94
When 10 mL of an aqueous solution of Fe2+ ions was titrated in the presence of dil H2SO4 using diphenylamine indicator, 15 mL of 0.02 M solution of K2Cr2O7 was required to get the end point. The molarity of the solution containing Fe2+ ions is x $$\times$$ 10$$-$$2 M. The value of x is __________. (Nearest integer)
JEE Main 2021 (Online) 25th July Morning Shift
95
Consider the complete combustion of butane, the amount of butane utilized to produce 72.0 g of water is ___________ $$\times$$ 10$$-$$1 g. (in nearest integer)
JEE Main 2021 (Online) 25th July Morning Shift
96
If the concentration of glucose (C6H12O6) in blood is 0.72 g L$$-$$1, the molarity of glucose in blood is ____________ $$\times$$ 10$$-$$3 M. (Nearest integer)

[Given : Atomic mass of C = 12, H = 1, O = 16 u]
JEE Main 2021 (Online) 22th July Evening Shift
97
4g equimolar mixture of NaOH and Na2CO3 contains x g of NaOH and y g of Na2CO3. The value of x is ____________ g. (Nearest integer)
JEE Main 2021 (Online) 20th July Evening Shift
98
250 mL of 0.5 M NaOH was added to 500 mL of 1 M HCl. The number of unreacted HCl molecules in the solution after complete reaction is ___________ $$\times$$ 1021. (Nearest integer)

(NA = 6.022 $$\times$$ 1023)
JEE Main 2021 (Online) 20th July Morning Shift
99
An average person needs about 10000 kJ energy per day. The amount of glucose (molar mass = 180.0 g mol$$-$$1) needed to meet this energy requirement is ____________ g.

(Use : $$\Delta$$CH(glucose) = $$-$$2700 kJ mol$$-$$1)
JEE Main 2021 (Online) 20th July Morning Shift
100
10.0 mL of Na2CO3 solution is titrated against 0.2 M HCl solution. The following titre values were obtained in 5 readings :

4.8 mL, 4.9 mL, 5.0 mL, 5.0 mL and 5.0 mL

Based on these readings, and convention of titrimetric estimation the concentration of Na2CO3 solution is ___________ mM.

(Round off to the Nearest Integer).
JEE Main 2021 (Online) 18th March Evening Shift
101
__________ grams of 3-Hydroxy propanal (MW = 74) must be dehydrated to produce 7.8 g of acrolein (MW = 56) (C3H4O) if the percentage yield is 64. (Round off to the Nearest Integer).

[Given : Atomic masses : C : 12.0 u, H : 1.0 u, O : 16.0 u ]
JEE Main 2021 (Online) 18th March Morning Shift
102
A reaction of 0.1 mole of Benzylamine with bromomethane gave 23 g of Benzyl trimethyl ammonium bromide. The number of moles of bromomethane consumed in this reaction are n $$\times$$ 10$$-$$1, when n = __________. (Round off to the Nearest Integer).

(Given : Atomic masses : C : 12.0 u, H : 1.0 u, N : 14.0 u, Br : 80.0 u]
JEE Main 2021 (Online) 18th March Morning Shift
103
Complete combustion of 3g of ethane gives x $$\times$$ 1022 molecules of water. The value of x is __________. (Round off to the Nearest Integer). [Use : NA = 6.023 $$\times$$ 1023; Atomic masses in u : C : 12.0; O : 16.0; H : 1.0]
JEE Main 2021 (Online) 18th March Morning Shift
104
JEE Main 2021 (Online) 17th March Evening Shift Chemistry - Some Basic Concepts of Chemistry Question 167 English
Consider the above reaction. The percentage yield of amide product is __________. (Round off to the Nearest Integer).

(Given : Atomic mass : C : 12.0 u, H : 1.0 u, N : 14.0 u, O : 16.0 u, Cl : 35.5 u)
JEE Main 2021 (Online) 17th March Evening Shift
105
15 mL of aqueous solution of Fe2+ in acidic medium completely reacted with 20 mL of 0.03 M aqueous Cr2O$$_7^{2 - }$$. The molarity of the Fe2+ solution is __________ $$\times$$ 10-2 M. (Round off to the Nearest Integer).
JEE Main 2021 (Online) 17th March Morning Shift
106
The mole fraction of a solute in a 100 molal aqueous solution is ___________ $$\times$$ 10$$-$$2. (Round off to the Nearest Integer).

[Given : Atomic masses : H : 1.0 u, O : 16.0 u ]
JEE Main 2021 (Online) 17th March Morning Shift
107
When 35 mL of 0.15 M lead nitrate solution is mixed with 20 mL of 0.12 M chromic sulphate solution, _________ $$\times$$ 10$$-$$5 moles of lead sulphate precipitate out. (Round off to the Nearest Integer).
JEE Main 2021 (Online) 16th March Evening Shift
108
Complete combustion of 750 g of an organic compound provides 420 g of CO2 and 210 g of H2O. The percentage composition of carbon and hydrogen in organic compound is 15.3 and ___________ respectively. (Round off to the Nearest Integer).
JEE Main 2021 (Online) 16th March Morning Shift
109
$$2MnO_4^ - + b{C_2}O_4^{2 - } + c{H^ + } \to xM{n^{2 + }} + yC{O_2} + z{H_2}O$$

If the above equation is balanced with integer coefficients, the value of c is ___________. (Round off to the Nearest Integer).
JEE Main 2021 (Online) 16th March Morning Shift
110
A 6.50 molal solution of KOH (aq.) has a density of 1.89 g cm$$-$$3. The molarity of the solution is ____________ mol dm$$-$$3. (Round off to the Nearest Integer).

[Atomic masses : K : 39.0 u; O : 16.0 u; H : 1.0 u]
JEE Main 2021 (Online) 16th March Morning Shift
111
The NaNO3 weighed out to make 50 mL of an aqueous solution containing 70.0 mg Na+ per mL is _________ g. (Rounded off to the nearest integer)

[Given : Atomic weight in g mol$$-$$1 - Na : 23; N : 14; O : 16]
JEE Main 2021 (Online) 26th February Evening Shift
112
The number of significant figures in 50000.020 $$\times$$ 10$$-$$3 is _____________.
JEE Main 2021 (Online) 26th February Morning Shift
113
In basic medium $$Cr{O_4}^{2 - }$$ oxidises $${S_2}{O_3}^{2 - }$$ to form $$S{O_4}^{2 - }$$ and itself changes into $$Cr{(OH)_4}^ - $$. The volume of 0.154 M $$Cr{O_4}^{2 - }$$ required to react with 40 mL of 0.25 M $${S_2}{O_3}^{2 - }$$ is __________ mL. (Rounded off to the nearest integer)
JEE Main 2021 (Online) 25th February Morning Shift
114
The formula of a gaseous hydrocarbon which requires 6 times of its own volume of O2 for complete oxidation and produces 4 times its own volume of CO2 is CxHy. The value of y is _____________.
JEE Main 2021 (Online) 24th February Evening Shift
115
1.86 g of aniline completely reacts to form acetanilide. 10% of the product is lost during purification. Amount of acetanilide obtained after purification (in g) is __________ $$\times$$ 10$$-$$2.
JEE Main 2021 (Online) 24th February Evening Shift
116
4.5 g of compound A (MW = 90) was used to make 250 mL of its aqueous solution. The molarity of the solution in M is x $$ \times $$ 10-1.
The value of x is _______. (Rounded off to the nearest integer)
JEE Main 2021 (Online) 24th February Morning Shift
117
Consider the following equations :
2Fe2+ + H2O2 $$ \to $$ xA + yB
(in basic medium)
2MnO4- + 6H+ + 5H2O2 $$ \to $$ x'C + y'D + z'E
(in acidic medium)
The sum of the stoichiometric coefficients x, y, x', y', and z' for products A, B, C, D and E, respectively, is ______.
JEE Main 2020 (Online) 4th September Evening Slot
118
A 20.0 mL solution containing 0.2 g impure H2O2 reacts completely with 0.316 g of KMnO4 in acid solution. The purity of H2O2 (in %) is _____________
(mol. wt. of H2O2 = 34; mol. wt. of KMnO4 = 158)
JEE Main 2020 (Online) 4th September Morning Slot
119
The mass of ammonia in grams produced when 2.8 kg of dinitrogen quantitatively reacts with 1 kg of dihydrogen is _______.
JEE Main 2020 (Online) 4th September Morning Slot
120
6.023 $$ \times $$ 1022 molecules are present in 10 g of a substance 'x'. The molarity of a solution containing 5 g of substance 'x' in 2 L solution is _____ × 10-3
JEE Main 2020 (Online) 3rd September Evening Slot
121
The volume (in mL) of 0.1 N NaOH required to neutralise 10 mL of 0.1 N phosphinic acid is ___________.
JEE Main 2020 (Online) 3rd September Evening Slot
122
The mole fraction of glucose (C6H12O6 ) in an aqueous binary solution is 0.1. The mass percentage of water in it, to the nearest integer, is _______.
JEE Main 2020 (Online) 3rd September Morning Slot
123
The volume strength of 8.9 M H2O2 solution calculated at 273 K and 1 atm is ______. (R = 0.0821 L atm K-1 mol-1) (rounded off ot the nearest integer)
JEE Main 2020 (Online) 3rd September Morning Slot
124
The ratio of the mass percentages of ‘C & H’ and ‘C & O’ of a saturated acyclic organic compound ‘X’ are 4 : 1 and 3 : 4 respectively. Then, the moles of oxygen gas required for complete combustion of two moles of organic compound ‘X’ is ________.
JEE Main 2020 (Online) 2nd September Evening Slot
125
10.30 mg of O2 is dissolved into a liter of sea water of density 1.03 g/mL. The concentration of O2 in ppm is__________.
JEE Main 2020 (Online) 9th January Evening Slot
126
The molarity of HNO3 in a sample which has density 1.4 g/mL and mass percentage of 63% is _____.
(Molecular Weight of HNO3 = 63)
JEE Main 2020 (Online) 9th January Morning Slot
127
The hardness of a water sample containing 10–3 M MgSO4 expressed as CaCO3 equivalents (in ppm) is ______.
(molar mass of MgSO4 is 120.37 g/mol)
JEE Main 2020 (Online) 9th January Morning Slot
128
The volume (in mL) of 0.125 M AgNO3 required to quantitatively precipitate chloride ions in 0.3 g of [Co(NH3)6]Cl3 is ________.
M[Co(NH3)6Cl3] = 267.46 g/mol
MAgNO3 = 169.87 g/mol
JEE Main 2020 (Online) 8th January Morning Slot
129
Ferrous sulphate heptahydrate is used to fortify foods with iron. The amount (in grams) of the salt required to achieve 10 ppm of iron in 100 kg of wheat is _______.
Atomic weight : Fe = 55.85; S = 32.00; O = 16.00
JEE Main 2020 (Online) 8th January Morning Slot
130
The flocculation value of HCl for arsenic sulphide sol.
is 30 m mol L-1 If H2SO4 is used for the flocculatiopn of arsenic sulphide, the amount in grams, of H2SO4 in 250 ml required for the above purposed is ______.
(molecular mass of H2SO4 = 98 g/mol)
JEE Main 2020 (Online) 7th January Evening Slot