MCQ (Single Correct Answer)

1

Given below are two statements :

Statement (I): NaCl is added to the ice at 0°C, present in the ice cream box to prevent the melting of ice cream.

Statement (II): On addition of NaCl to ice at 0°C, there is a depression in freezing point.

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

JEE Main 2025 (Online) 29th January Evening Shift
2

1.24 g of AX2 (molar mass 124 g mol−1) is dissolved in 1 kg of water to form a solution with boiling point of 100.015°C, while 25.4 g of AY2 (molar mass 250 g mol−1) in 2 kg of water constitutes a solution with a boiling point of 100.0260°C.

Kb(H2O) = 0.52 kg mol−1

Which of the following is correct?

JEE Main 2025 (Online) 29th January Morning Shift
3

Assume a living cell with 0.9% (w/w) of glucose solution (aqueous). This cell is immersed in another solution having equal mole fraction of glucose and water.
(Consider the data upto first decimal place only)

The cell will :

JEE Main 2025 (Online) 28th January Evening Shift
4

What is the freezing point depression constant of a solvent, 50 g of which contain 1 g non volatile solute (molar mass $256 \mathrm{~g} \mathrm{~mol}^{-1}$ ) and the decrease in freezing point is 0.40 K ?

JEE Main 2025 (Online) 28th January Morning Shift
5

Consider the given plots of vapour pressure (VP) vs temperature(T/K). Which amongst the following options is correct graphical representation showing $\Delta \mathrm{T}_{\mathrm{f}}$, depression in the freezing point of a solvent in a solution?

JEE Main 2025 (Online) 24th January Morning Shift
6

When a non-volatile solute is added to the solvent, the vapour pressure of the solvent decreases by 10 mm of Hg . The mole fraction of the solute in the solution is 0.2 . What would be the mole fraction of the solvent if decrease in vapour pressure is 20 mm of Hg ?

JEE Main 2025 (Online) 23rd January Evening Shift
7

Consider a binary solution of two volatile liquid components 1 and $2 . x_1$ and $y_1$ are the mole fractions of component 1 in liquid and vapour phase, respectively. The slope and intercept of the linear plot of $\frac{1}{x_1}$ vs $\frac{1}{y_1}$ are given respectively as :

JEE Main 2025 (Online) 23rd January Evening Shift
8

Arrange the following solutions in order of their increasing boiling points.

(i) $10^{-4} \mathrm{M} \mathrm{NaCl}$

(ii) $10^{-4} \mathrm{M}$ Urea

(iii) $10^{-3} \mathrm{M} \mathrm{NaCl}$

(iv) $10^{-2} \mathrm{M} \mathrm{NaCl}$

JEE Main 2025 (Online) 22nd January Morning Shift
9

$$0.05 \mathrm{M} \mathrm{~CuSO}_4$$ when treated with $$0.01 \mathrm{M} \mathrm{~K}_2 \mathrm{Cr}_2 \mathrm{O}_7$$ gives green colour solution of $$\mathrm{Cu}_2 \mathrm{Cr}_2 \mathrm{O}_7$$. The two solutions are separated as shown below : [SPM : Semi Permeable Membrane]

JEE Main 2024 (Online) 9th April Morning Shift Chemistry - Solutions Question 16 English

Due to osmosis :

JEE Main 2024 (Online) 9th April Morning Shift
10
We have three aqueous solutions of $\mathrm{NaCl}$ labelled as ' $\mathrm{A}$ ', ' $\mathrm{B}$ ' and ' $\mathrm{C}$ ' with concentration $0.1 \mathrm{M}$, $0.01 \mathrm{M}$ and $0.001 \mathrm{M}$, respectively. The value of van 't Hoff factor(i) for these solutions will be in the order :
JEE Main 2024 (Online) 1st February Morning Shift
11

Identify the mixture that shows positive deviations from Raoult's Law

JEE Main 2024 (Online) 31st January Morning Shift
12

The solution from the following with highest depression in freezing point/lowest freezing point is

JEE Main 2024 (Online) 30th January Evening Shift
13

What happens to freezing point of benzene when small quantity of napthalene is added to benzene?

JEE Main 2024 (Online) 30th January Morning Shift
14

A solution of two miscible liquids showing negative deviation from Raoult's law will have :

JEE Main 2024 (Online) 27th January Morning Shift
15

What weight of glucose must be dissolved in $$100 \mathrm{~g}$$ of water to lower the vapour pressure by $$0.20 \mathrm{~mm} ~\mathrm{Hg}$$ ?

(Assume dilute solution is being formed)

Given : Vapour pressure of pure water is $$54.2 \mathrm{~mm} ~\mathrm{Hg}$$ at room temperature. Molar mass of glucose is $$180 \mathrm{~g} \mathrm{~mol}^{-1}$$

JEE Main 2023 (Online) 11th April Evening Shift
16
Evaluate the following statements for their correctness.

A. The elevation in boiling point temperature of water will be same for $0.1 \mathrm{M} \, \mathrm{NaCl}$ and $0.1 \mathrm{M}$ urea.

B. Azeotropic mixtures boil without change in their composition.

C. Osmosis always takes place from hypertonic to hypotonic solution.

D. The density of $32 \% \, \mathrm{H}_{2} \mathrm{SO}_{4}$ solution having molarity $4.09 ~\mathrm{M}$ is approximately $1.26 \mathrm{~g} \mathrm{~mL}^{-1}$

E. A negatively charged sol is obtained when KI solution is added to silver nitrate solution.

Choose the correct answer from the options given below :
JEE Main 2023 (Online) 31st January Evening Shift
17

Match List I with List II

List I List II
A. van't Hoff factor, i I. Cryoscopic constant
B. $$\mathrm{k_f}$$ II. Isotonic solutions
C. Solutions with same osmotic pressure III. $$\mathrm{\frac{Normal\,molar\,mass}{Abnormal\,molar\,mass}}$$
D. Azeotropes IV. Solutions with same composition of vapour above it

Choose the correct answer from the options given below :

JEE Main 2023 (Online) 29th January Evening Shift
18

In the depression of freezing point experiment

A. Vapour pressure of the solution is less than that of pure solvent

B. Vapour pressure of the solution is more than that of pure solvent

C. Only solute molecules solidify at the freezing point

D. Only solvent molecules solidify at the freezing point

Choose the most appropriate answer from the options given below :

JEE Main 2023 (Online) 24th January Morning Shift
19

Boiling point of a $$2 \%$$ aqueous solution of a non-volatile solute A is equal to the boiling point of $$8 \%$$ aqueous solution of a non-volatile solute B. The relation between molecular weights of A and B is

JEE Main 2022 (Online) 27th July Morning Shift
20

Two solutions A and B are prepared by dissolving 1 g of non-volatile solutes X and Y, respectively in 1 kg of water. The ratio of depression in freezing points for A and B is found to be 1 : 4. The ratio of molar masses of X and Y is

JEE Main 2022 (Online) 25th July Evening Shift
21

The depression in freezing point observed for a formic acid solution of concentration $$0.5 \mathrm{~mL} \mathrm{~L}^{-1}$$ is $$0.0405^{\circ} \mathrm{C}$$. Density of formic acid is $$1.05 \mathrm{~g} \mathrm{~mL}^{-1}$$. The Van't Hoff factor of the formic acid solution is nearly : (Given for water $$\mathrm{k}_{\mathrm{f}}=1.86\, \mathrm{k} \,\mathrm{kg}\,\mathrm{mol}^{-1}$$ )

JEE Main 2022 (Online) 25th July Morning Shift
22

For a solution of the gases A, B, C and D in water at 298 K, the values of Henry's law constant (KH) are 30.40, 2.34, 1.56 $$\times$$ 10$$-$$5 and 0.513 k bar respectively. In the given graph, the lines marked as 'p' and 's' correspond respectively to :

JEE Main 2022 (Online) 30th June Morning Shift Chemistry - Solutions Question 58 English

JEE Main 2022 (Online) 30th June Morning Shift
23

Given below are two statements : one is labelled as Assertion (A) and the other is labelled as Reason (R).

Assertion (A) : At 10$$^\circ$$C, the density of a 5 M solution of KCl [atomic masses of K & Cl are 39 & 35.5 g mol$$-$$1 respectively], is 'x' g ml$$-$$1. The solution is cooled to $$-$$21$$^\circ$$C. The molality of the solution will remain unchanged.

Reason (R) : The molality of a solution does not change with temperature as mass remains unaffected with temperature.

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

JEE Main 2022 (Online) 27th June Morning Shift
24

Solute A associates in water. When 0.7 g of solute A is dissolved in 42.0 g of water, it depresses the freezing point by 0.2$$^\circ$$C. The percentage association of solute A in water, is :

[Given : Molar mass of A = 93 g mol$$-$$1. Molal depression constant of water is 1.86 K kg mol$$-$$1.]

JEE Main 2022 (Online) 25th June Evening Shift
25
Which one of the following 0.10 M aqueous solutions will exhibit the largest freezing point depression?
JEE Main 2021 (Online) 31st August Morning Shift
26
Which one of the following 0.06 M aqueous solutions has lowest freezing point?
JEE Main 2021 (Online) 22th July Evening Shift
27
A set of solutions is prepared using 180 g of water as a solvent and 10 g of different nonvolatile solutes A, B and C. The relative lowering of vapour pressure in the presence of these solutes are in the order :

[Given, molar mass of A = 100 g mol–1; B = 200 g mol–1; C = 10,000 g mol–1]
JEE Main 2020 (Online) 6th September Evening Slot
28
The size of a raw mango shrinks to a much smaller size when kept in a concentrated salt solution. Which one of the following processes can explain this?
JEE Main 2020 (Online) 2nd September Evening Slot
29
A graph of vapour pressure and temperature for three different liquids X, Y, and Z is shown below : JEE Main 2020 (Online) 8th January Morning Slot Chemistry - Solutions Question 105 English The following inferences are made :
(A) X has higher intermolecular interactions compared to Y.
(B) X has lower intermolecular interactions compared to Y.
(C) Z has lower intermolecular interactions compared to Y.
The correct inference (s) is / are :
JEE Main 2020 (Online) 8th January Morning Slot
30
Two open beakers one containing a solvent and the other containing a mixture of that solvent with a non voltatile solute are together selated in a container. Over time :
JEE Main 2020 (Online) 7th January Evening Slot
31
At 35oC, the vapour pressure of CS2 is 512 mm. Hg and that of acetone is 344 mm Hg. A solution of CS2 in acetone has a total vapour pressure of 600 mm Hg. The false statement amongst the following is :
JEE Main 2020 (Online) 7th January Morning Slot
32
A solution is prepared by dissolving 0.6 g of urea (molar mass = 60 g mol–1) and 1.8 g of glucose (molar mass = 180 g mol–1) in 100 mL of water at 27oC. The osmotic pressure of the solution is :
(R = 0.08206 L atm K–1 mol–1)
JEE Main 2019 (Online) 12th April Evening Slot
33
1 g of a non-volatile non-electrolyte solute is dissolved in 100 g of two different solvents A and B whose ebullioscopic constants are in the ratio of 1 : 5. The ratio of the elevation in their boiling points, $${{\Delta {T_b}(A)} \over {\Delta {T_b}(B)}}$$, is :
JEE Main 2019 (Online) 10th April Evening Slot
34
At room temperature, a dilute solution of urea is prepared by dissolving 0.60 of urea in 360 g of water. If the vapour pressure of pure water at this temperature is 35 mm Hg, lowering of vapour pressure will be. (molar mass of urea = 60 g mol–1)
JEE Main 2019 (Online) 10th April Morning Slot
35
Molal depression constant for a solvent is 4.0 kg mol–1. The depression in the freezing point of the solvent for 0.03 mol kg–1 solution of K2SO4 is :
(Assume complete dissociation of the electrolyte)
JEE Main 2019 (Online) 9th April Evening Slot
36
Liquid 'M' and liquid 'N' form an ideal solution. The vapour pressures of pure liquids 'M' and 'N' are 450 and 700 mmHg, respectively, at the same temperature. Then correct statement is:
(xM = Mole fraction of 'M' in solution ;
xN = Mole fraction of 'N' in solution ;
yM = Mole fraction of 'M' in vapour phase ;
yN = Mole fraction of 'N' in vapour phase)
JEE Main 2019 (Online) 9th April Morning Slot
37
The osmotic pressure of a dilute solution of an ionic compound XY in water is four times that of a solution of 0.01 M BaCl2 in water. Assuming complete dissociation of the given ionic compounds in water, the concentration of XY (in mol L–1) in solution is :
JEE Main 2019 (Online) 9th April Morning Slot
38
For the solution of the gases w, x, y and z in water at 298K, the Henrys law constants (KH) are 0.5, 2, 35 and 40 kbar, respectively. The correct plot for the given data is :-
JEE Main 2019 (Online) 8th April Evening Slot
39
The vapour pressures of pure liquids A and B are 400 and 600 mmHg, respectively at 298 K on mixing the two liquids, the sum of their initial volume is equal ot the volume of the final mixture. The mole fraction of liquid B is 0.5 in the mixture, The vapour pressure of the final solution, the mole fractions of components A and B in vapour phase, respectively are :
JEE Main 2019 (Online) 8th April Morning Slot
40
Molecules of benzoic acid (C6H5COOH) dimerise in benzene. 'w' g of the acid dissolved in 30 g of benzene shows a depression in freezing point equal to 2K. If the percentage association of the acid to form dimmer in the solution is 80, then w is – (Its given that Kf = 5 K kg mol–1, Molar mass of benzoic acid = 122 g mol–1)
JEE Main 2019 (Online) 12th January Evening Slot
41
Freezing point of a 4% aqueous solution of X is equal to freezing point of 12% aqueous solution of Y. If molecular weight of X is A, then molecular weight of Y is -
JEE Main 2019 (Online) 12th January Morning Slot
42
K2Hgl4 is 40% ionised in aqueous solution. The value of its van't Hoff factor (i) is:
JEE Main 2019 (Online) 11th January Evening Slot
43
The freezing point of a diluted milk sample is found to be –0.2oC, while it should have been –0.5oC for pure milk. How much water has been added to pure milk to make the diluted sample?
JEE Main 2019 (Online) 11th January Morning Slot
44
Elevation in the boiling point for 1 molar solution of glucose is 2 K. The depression in the freezing point for 2 molal solution of glucose in the same solvent is 2 K. The relation between Kb and Kf is
JEE Main 2019 (Online) 10th January Evening Slot
45
Liquids A and B form an ideal solution in the entire composition range. At 350 K, the vaapor pressures of pure A and pure B are 7 $$ \times $$ 103 Pa and 12 $$ \times $$ 103 Pa, respectively . The composition of the vapor in equilibriumwith a solution containing 40 mole percent of A at this temperature is :
JEE Main 2019 (Online) 10th January Morning Slot
46
A solution containing 62 g ethylene glycol in 250 g water is cooled to $$-$$ 10oC. If Kf for water is 1.86 K kg mol$$-$$1 , the amount of water (in g) separated as ice is :
JEE Main 2019 (Online) 9th January Evening Slot
47
Which one of the following statements regarding Henry's law is not correct ?
JEE Main 2019 (Online) 9th January Morning Slot
48
The mass of a non-volatile, non-electrolyte solute (molar mass = 50 g mol-1 ) needed to be dissolved in 114 g octane to reduce its vapour pressure to 75%, is :
JEE Main 2018 (Online) 16th April Morning Slot
49
For 1 molal aqueous solution of the following compounds, which one will show the highest freezing point?
JEE Main 2018 (Offline)
50
Two 5 molal solutions are prepared by dissolving a non-electrolyte non-volatile solute separately in the solvents X and Y. The molecular weights of the solvents are Mx and My, respectively where Mx = $${3 \over 4}$$ My. The relative lowering of vapor pressure of the solution in X is ''m'' times that of the solution in Y. Given that the number of moles of solute is very small in comparison to that of the solvent, the value of ''m'' is :
JEE Main 2018 (Online) 15th April Evening Slot
51
A solution is prepared by mixing 8.5 g of CH2Cl2 and 11.95 g of CHCl3 . If vapour pressure of CH2Cl2 and CHCl3 at 298 K are 415 and 200 mmHg respectively, the mole fraction of CHCl3 in vapour form is : (Molar mass of Cl = 35.5 g mol−1)
JEE Main 2017 (Online) 9th April Morning Slot
52
5 g of Na2SO4 was dissolved in x g of H2O. The change in freezing point was found to be 3.82oC. If Na2SO4 is 81.5% ionised, the value of x

(Kf for water=1.86oC kg mol−1) is approximately :

(molar mass of S = 32 g mol−1 and that of Na = 23 g mol−1)
JEE Main 2017 (Online) 8th April Morning Slot
53
The freezing point of benzene decreases by 0.450C when 0.2 g of acetic acid is added to 20g of benzene. If acetic acid associates to form a dimer in benzene, percentage association of acetic acid in benzene will be: (Kf for benzene = 5.12 K kg mol–1)
JEE Main 2017 (Offline)
54
An aqueous solution of a salt MX2 at certain temperature has a van’t Hoff factor of 2. The degree of dissociation for this solution of the salt is :
JEE Main 2016 (Online) 10th April Morning Slot
55
The solubility of N2 in water at 300 K and 500 torr partial pressure is 0.01 g L−1. The solubility (in g L−1) at 750 torr partial pressure is :
JEE Main 2016 (Online) 9th April Morning Slot
56
18 g glucose (C6H12O6) is added to 178.2 g water. The vapor pressure of water (in torr) for this aqueous solution is :
JEE Main 2016 (Offline)
57
The vapour pressure of acetone at 20oC is 185 torr. When 1.2 g of a non-volatile substance was dissolved in 100 g of acetone at 20oC, its vapour pressure was 183 torr. The molar mass (g mol-1) of the substance is:
JEE Main 2015 (Offline)
58
Consider separate solutions of 0.500 M C2H5OH(aq), 0.100 M Mg3(PO4)2(aq), 0.250 M KBr(aq) and 0.125 M Na3PO4(aq) at 25oC. Which statement is true about these solutions, assuming all salts to be strong electrolytes?
JEE Main 2014 (Offline)
59
Kf for water is 1.86K kg mol–1. If your automobile radiator holds 1.0 kg of water, how many grams of ethylene glycol (C2H6O2) must you add to get the freezing point of the solution lowered to –2.8oC ?
AIEEE 2012
60
The degree of dissociation ($$\alpha$$ ) of a weak electrolyte, AxBy is related to van’t Hoff factor (i) by the expression :
AIEEE 2011
61
Ethylene glycol is used as an antifreeze in a cold climate. Mass of ethylene glycol which should be added to 4 kg of water to prevent it from freezing at −6oC will be : [Kf for water = 1.86 K kg mol−1 , and molar mass of ethylene glycol = 62 g mol−1 )
AIEEE 2011
62
If sodium sulphate is considered to be completely dissociated into cations and anions in aqueous solution, the change in freezing point of water (∆Tf), when 0.01 mol of sodium sulphate is dissolved in 1 kg of water, is (Kf = 1.86 K kg mol–1)
AIEEE 2010
63
On mixing, heptane and octane form an ideal solution. At 373 K, the vapour pressures of the two liquid components (heptane and octane) are 105 kPa and 45 kPa respectively. Vapour pressure of the solution obtained by mixing 25.0g of heptane and 35 g of octane will be (molar mass of heptane = 100 g mol–1 and of octane = 114 g mol–1)
AIEEE 2010
64
A binary liquid solution is prepared by mixing n-heptane and ethanol. Which one of the following statements is correct regarding the behaviour of the solution ?
AIEEE 2009
65
Two liquids X and Y form an ideal solution. At 300K, vapour pressure of the solution containing 1 mol of X and 3 mol of Y is 550 mm Hg. At the same temperature, if 1 mol of Y is further added to this solution, vapour pressure of the solution increases by 10 mm Hg. Vapour pressure (in mm Hg) of X and Y in their pure states will be, respectively :
AIEEE 2009
66
At 80oC, the vapour pressure of pure liquid ‘A’ is 520 mm Hg and that of pure liquid ‘B’ is 1000 mm Hg. If a mixture solution of ‘A’ and ‘B’ boils at 80oC and 1 atm pressure, the amount of ‘A’ in the mixture is (1 atm = 760 mm Hg)
AIEEE 2008
67
The vapour pressure of water at 20oC is 17.5 mm Hg. If 18 g of glucose (C6H12O6) is added to 178.2 g of water at 20oC, the vapour pressure of the resulting solution will be
AIEEE 2008
68
A 5.25 % solution of a substance is isotonic with a 1.5% solution of urea (molar mass = 60 g mol−1) in the same solvent. If the densities of both the solutions are assumed to be equal to 1.0 g cm−3, molar mass of the substance will be
AIEEE 2007
69
A mixture of ethyl alcohol and propyl alcohol has a vapour pressure of 290 mm at 300 K. The vapour pressure of propyl alcohol is 200 mm. If the mole fraction of ethyl alcohol is 0.6, its vapour pressure (in mm) at the same temperature will be
AIEEE 2007
70
Among the following mixtures, dipole-dipole as the major interaction, is present in
AIEEE 2006
71
18 g of glucose (C6H12O6) is added to 178.2 g of water. The vapour pressure of water for this aqueous solution at 100oC is
AIEEE 2006
72
If $$\alpha$$ is the degree of dissociation of Na2SO4, the vant Hoff’s factor (i) used for calculating the molecular mass is :
AIEEE 2005
73
Equimolar solutions in the same solvent have
AIEEE 2005
74
Benzene and toluene form nearly ideal solutions. At 20 oC, the vapour pressure of benzene is 75 torr and that of toluene is 22 torr. The partial vapour pressure of benzene at 20 oC for a solution containing 78 g of benzene and 46 g of toluene in torr is
AIEEE 2005
75
For which of the following parameters the structural isomers C2H5OH and CH3OCH3 would be expected to have the same values? (Assume ideal behaviour)
AIEEE 2004
76
Which of the following liquid pairs shows a positive deviation from Raoult’s law?
AIEEE 2004
77
Which one of the following aqueous solutions will exhibit highest boiling point?
AIEEE 2004
78
Which one of the following statements is false?
AIEEE 2004
79
A pressure cooker reduces cooking time for food because
AIEEE 2003
80
In a 0.2 molal aqueous solution of a weak acid HX the degree of ionization is 0.3. Taking kf for water as 1.85, the freezing point of the solution will be nearest to
AIEEE 2003
81
If liquids A and B form an ideal solution
AIEEE 2003
82
In a mixture of A and B, components show negative deviation when :
AIEEE 2002
83
Freezing point of an aqueous solution is (-0.186)oC. Elevation of boiling point of the same solution is Kb = 0.512 oC, Kf = 1.86 oC, find the increase in boiling point.
AIEEE 2002

Numerical

1

If A2B is 30% ionised in an aqueous solution, then the value of van't Hoff factor (i) is _______ × 10−1.

JEE Main 2025 (Online) 29th January Morning Shift
2

The vapor pressure of pure benzene and methyl benzene at $$27^{\circ} \mathrm{C}$$ is given as 80 Torr and 24 Torr, respectively. The mole fraction of methyl benzene in vapor phase, in equilibrium with an equimolar mixture of those two liquids (ideal solution) at the same temperature is _________ $$\times 10^{-2}$$ (nearest integer)

JEE Main 2024 (Online) 9th April Evening Shift
3

A solution containing $$10 \mathrm{~g}$$ of an electrolyte $$\mathrm{AB}_2$$ in $$100 \mathrm{~g}$$ of water boils at $$100.52^{\circ} \mathrm{C}$$. The degree of ionization of the electrolyte $$(\alpha)$$ is _________ $$\times 10^{-1}$$. (nearest integer)

[Given : Molar mass of $$\mathrm{AB}_2=200 \mathrm{~g} \mathrm{~mol}^{-1}, \mathrm{~K}_{\mathrm{b}}$$ (molal boiling point elevation const. of water) $$=0.52 \mathrm{~K} \mathrm{~kg} \mathrm{~mol}^{-1}$$, boiling point of water $$=100^{\circ} \mathrm{C} ; \mathrm{AB}_2$$ ionises as $$\mathrm{AB}_2 \rightarrow \mathrm{A}^{2+}+2 \mathrm{~B}^{-}]$$

JEE Main 2024 (Online) 8th April Morning Shift
4

When '$$x$$' $$\times 10^{-2} \mathrm{~mL}$$ methanol (molar mass $$=32 \mathrm{~g}$$' density $$=0.792 \mathrm{~g} / \mathrm{cm}^3$$) is added to $$100 \mathrm{~mL}$$. water (density $$=1 \mathrm{~g} / \mathrm{cm}^3$$), the following diagram is obtained.

JEE Main 2024 (Online) 6th April Evening Shift Chemistry - Solutions Question 10 English

$$x=$$ ________ (nearest integer).

[Given : Molal freezing point depression constant of water at $$273.15 \mathrm{~K}$$ is $$1.86 \mathrm{~K} \mathrm{~kg} \mathrm{~mol}^{-1}$$]

JEE Main 2024 (Online) 6th April Evening Shift
5

Considering acetic acid dissociates in water, its dissociation constant is $$6.25 \times 10^{-5}$$. If $$5 \mathrm{~mL}$$ of acetic acid is dissolved in 1 litre water, the solution will freeze at $$-x \times 10^{-2}{ }^{\circ} \mathrm{C}$$, provided pure water freezes at $$0{ }^{\circ} \mathrm{C}$$.

$$x=$$ _________. (Nearest integer)

$$\begin{aligned} \text{Given :} \quad & \left(\mathrm{K}_{\mathrm{f}}\right)_{\text {water }}=1.86 \mathrm{~K} \mathrm{~kg} \mathrm{~mol}-1 \\ & \text { density of acetic acid is } 1.2 \mathrm{~g} \mathrm{~mol}^{-1} \text {. } \\ & \text { molar mass of water }=18 \mathrm{~g} \mathrm{~mol}^{-1} \text {. } \\ & \text { molar mass of acetic acid= } 60 \mathrm{~g} \mathrm{~mol}^{-1} \text {. } \\ & \text { density of water }=1 \mathrm{~g} \mathrm{~cm}^{-3} \end{aligned}$$

Acetic acid dissociates as $$\mathrm{CH}_3 \mathrm{COOH} \rightleftharpoons \mathrm{CH}_3 \mathrm{COO}^{\ominus}+\mathrm{H}^{\oplus}$$

JEE Main 2024 (Online) 5th April Evening Shift
6

An artificial cell is made by encapsulating $$0.2 \mathrm{~M}$$ glucose solution within a semipermeable membrane. The osmotic pressure developed when the artificial cell is placed within a $$0.05 \mathrm{~M}$$ solution of $$\mathrm{NaCl}$$ at $$300 \mathrm{~K}$$ is ________ $$\times 10^{-1}$$ bar. (nearest integer).

[Given : $$\mathrm{R}=0.083 \mathrm{~L} \mathrm{~bar} \mathrm{~mol}^{-1} \mathrm{~K}^{-1}$$ ]

Assume complete dissociation of $$\mathrm{NaCl}$$

JEE Main 2024 (Online) 5th April Morning Shift
7

$$2.7 \mathrm{~kg}$$ of each of water and acetic acid are mixed. The freezing point of the solution will be $$-x^{\circ} \mathrm{C}$$. Consider the acetic acid does not dimerise in water, nor dissociates in water. $$x=$$ ________ (nearest integer)

[Given: Molar mass of water $$=18 \mathrm{~g} \mathrm{~mol}^{-1}$$, acetic acid $$=60 \mathrm{~g} \mathrm{~mol}^{-1}$$

$${ }^{\mathrm{K}_{\mathrm{f}}} \mathrm{H}_2 \mathrm{O}: 1.86 \mathrm{~K} \mathrm{~kg} \mathrm{~mol}^{-1}$$

$$\mathrm{K}_{\mathrm{f}}$$ acetic acid: $$3.90 \mathrm{~K} \mathrm{~kg} \mathrm{~mol}^{-1}$$

freezing point: $$\mathrm{H}_2 \mathrm{O}=273 \mathrm{~K}$$, acetic acid $$=290 \mathrm{~K}$$]

JEE Main 2024 (Online) 4th April Evening Shift
8

$$2.5 \mathrm{~g}$$ of a non-volatile, non-electrolyte is dissolved in $$100 \mathrm{~g}$$ of water at $$25^{\circ} \mathrm{C}$$. The solution showed a boiling point elevation by $$2^{\circ} \mathrm{C}$$. Assuming the solute concentration is negligible with respect to the solvent concentration, the vapor pressure of the resulting aqueous solution is _________ $$\mathrm{mm}$$ of $$\mathrm{Hg}$$ (nearest integer)

[Given : Molal boiling point elevation constant of water $\left(\mathrm{K}_{\mathrm{b}}\right)=0.52 \mathrm{~K} . \mathrm{kg} \mathrm{mol}^{-1}$, $$1 \mathrm{~atm}$$ pressure $$=760 \mathrm{~mm}$$ of $$\mathrm{Hg}$$, molar mass of water $$=18 \mathrm{~g} \mathrm{~mol}^{-1}]$$

JEE Main 2024 (Online) 4th April Morning Shift
9
Mass of ethylene glycol (antifreeze) to be added to $18.6 \mathrm{~kg}$ of water to protect the freezing point at $-24^{\circ} \mathrm{C}$ is ________ $\mathrm{kg}$ (Molar mass in $\mathrm{g} ~\mathrm{mol}^{-1}$ for ethylene glycol $62, \mathrm{~K}_f$ of water $=1.86 \mathrm{~K}$ $\mathrm{kg} ~\mathrm{mol}^{-1}$ )
JEE Main 2024 (Online) 1st February Evening Shift
10

The osmotic pressure of a dilute solution is $$7 \times 10^5 \mathrm{~Pa}$$ at $$273 \mathrm{~K}$$. Osmotic pressure of the same solution at $$283 \mathrm{~K}$$ is _________ $$\times 10^4 \mathrm{Nm}^{-2}$$.

JEE Main 2024 (Online) 29th January Morning Shift
11
The vapour pressure of $30 \%(\mathrm{w} / \mathrm{v})$ aqueous solution of glucose is __________ $\mathrm{mm} ~\mathrm{Hg}$ at $25^{\circ} \mathrm{C}$.

[Given : The density of $30 \%$ (w/v), aqueous solution of glucose is $1.2 \mathrm{~g} \mathrm{~cm}^{-3}$ and vapour pressure of pure water is $24 \mathrm{~mm}~ \mathrm{Hg}$.]

(Molar mass of glucose is $180 \mathrm{~g} \mathrm{~mol}^{-1}$.)
JEE Main 2023 (Online) 15th April Morning Shift
12

Sea water contains $$29.25 \% ~\mathrm{NaCl}$$ and $$19 \% ~\mathrm{MgCl}_{2}$$ by weight of solution. The normal boiling point of the sea water is _____________ $${ }^{\circ} \mathrm{C}$$ (Nearest integer)

Assume $$100 \%$$ ionization for both $$\mathrm{NaCl}$$ and $$\mathrm{MgCl}_{2}$$

Given : $$\mathrm{K}_{\mathrm{b}}\left(\mathrm{H}_{2} \mathrm{O}\right)=0.52 \mathrm{~K} \mathrm{~kg} \mathrm{~mol}^{-1}$$

Molar mass of $$\mathrm{NaCl}$$ and $$\mathrm{MgCl}_{2}$$ is 58.5 and 95 $$\mathrm{g} \mathrm{~mol}^{-1}$$ respectively.

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

Solution of $$12 \mathrm{~g}$$ of non-electrolyte (A) prepared by dissolving it in $$1000 \mathrm{~mL}$$ of water exerts the same osmotic pressure as that of $$0.05 ~\mathrm{M}$$ glucose solution at the same temperature. The empirical formula of $$\mathrm{A}$$ is $$\mathrm{CH}_{2} \mathrm{O}$$. The molecular mass of $$\mathrm{A}$$ is __________ g. (Nearest integer)

JEE Main 2023 (Online) 13th April Morning Shift
14

80 mole percent of $$\mathrm{MgCl}_{2}$$ is dissociated in aqueous solution. The vapour pressure of $$1.0 ~\mathrm{molal}$$ aqueous solution of $$\mathrm{MgCl}_{2}$$ at $$38^{\circ} \mathrm{C}$$ is ____________ $$\mathrm{mm} ~\mathrm{Hg.} ~\mathrm{(Nearest} ~\mathrm{integer)}$$

Given : Vapour pressure of water at $$38^{\circ} \mathrm{C}$$ is $$50 \mathrm{~mm} ~\mathrm{Hg}$$

JEE Main 2023 (Online) 12th April Morning Shift
15

0.004 M K$$_2$$SO$$_4$$ solution is isotonic with 0.01 M glucose solution. Percentage dissociation of K$$_2$$SO$$_4$$ is ___________ (Nearest integer)

JEE Main 2023 (Online) 11th April Morning Shift
16

An aqueous solution of volume $$300 \mathrm{~cm}^{3}$$ contains $$0.63 \mathrm{~g}$$ of protein. The osmotic pressure of the solution at $$300 \mathrm{~K}$$ is 1.29 mbar. The molar mass of the protein is ___________ $$\mathrm{g} ~\mathrm{mol}^{-1}$$

Given : R = 0.083 L bar K$$^{-1}$$ mol$$^{-1}$$

JEE Main 2023 (Online) 10th April Evening Shift
17

If the degree of dissociation of aqueous solution of weak monobasic acid is determined to be 0.3, then the observed freezing point will be ___________% higher than the expected/theoretical freezing point. (Nearest integer)

JEE Main 2023 (Online) 10th April Morning Shift
18

If the boiling points of two solvents X and Y (having same molecular weights) are in the ratio $$2: 1$$ and their enthalpy of vaporizations are in the ratio $$1: 2$$, then the boiling point elevation constant of $$\mathrm{X}$$ is $$\underline{\mathrm{m}}$$ times the boiling point elevation constant of Y. The value of m is ____________ (nearest integer)

JEE Main 2023 (Online) 8th April Evening Shift
19

The vapour pressure vs. temperature curve for a solution solvent system is shown below.

JEE Main 2023 (Online) 8th April Morning Shift Chemistry - Solutions Question 27 English

The boiling point of the solvent is __________ $${ }^{\circ} \mathrm{C}$$.

JEE Main 2023 (Online) 8th April Morning Shift
20

Consider the following pairs of solution which will be isotonic at the same temperature. The number of pairs of solutions is / are ___________.

A. $$1 ~\mathrm{M}$$ aq. $$\mathrm{NaCl}$$ and $$2 ~\mathrm{M}$$ aq. urea

B. $$1 ~\mathrm{M}$$ aq. $$\mathrm{CaCl}_{2}$$ and $$1.5 ~\mathrm{M}$$ aq. $$\mathrm{KCl}$$

C. $$1.5 ~\mathrm{M}$$ aq. $$\mathrm{AlCl}_{3}$$ and $$2 ~\mathrm{M}$$ aq. $$\mathrm{Na}_{2} \mathrm{SO}_{4}$$

D. $$2.5 ~\mathrm{M}$$ aq. $$\mathrm{KCl}$$ and $$1 ~\mathrm{M}$$ aq. $$\mathrm{Al}_{2}\left(\mathrm{SO}_{4}\right)_{3}$$

JEE Main 2023 (Online) 6th April Evening Shift
21

Mass of Urea $$\left(\mathrm{NH}_{2} \mathrm{CONH}_{2}\right)$$ required to be dissolved in $$1000 \mathrm{~g}$$ of water in order to reduce the vapour pressure of water by $$25 \%$$ is _________ g. (Nearest integer)

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

JEE Main 2023 (Online) 6th April Morning Shift
22

$$20 \%$$ of acetic acid is dissociated when its $$5 \mathrm{~g}$$ is added to $$500 \mathrm{~mL}$$ of water. The depression in freezing point of such water is _________ $$\times 10^{-3}{ }^{\circ} \mathrm{C}$$.

Atomic mass of $$\mathrm{C}, \mathrm{H}$$ and $$\mathrm{O}$$ are 12,1 and 16 a.m.u. respectively.

[Given : Molal depression constant and density of water are $$1.86 \mathrm{~K} \mathrm{~kg} \mathrm{~mol}^{-1}$$ and $$1 \mathrm{~g} \mathrm{~cm}^{-3}$$ respectively.]

JEE Main 2023 (Online) 1st February Evening Shift
23

25 mL of an aqueous solution of KCl was found to require 20 mL of 1 M $$\mathrm{AgNO_3}$$ solution when titrated using $$\mathrm{K_2CrO_4}$$ as an indicator. What is the depression in freezing point of KCl solution of the given concentration? _________ (Nearest integer).

(Given : $$\mathrm{K_f=2.0~K~kg~mol^{-1}}$$)

Assume 1) 100% ionization and 2) density of the aqueous solution as 1 g mL$$^{-1}$$

JEE Main 2023 (Online) 1st February Morning Shift
24

At $$27^{\circ} \mathrm{C}$$, a solution containing $$2.5 \mathrm{~g}$$ of solute in $$250.0 \mathrm{~mL}$$ of solution exerts an osmotic pressure of $$400 \mathrm{~Pa}$$. The molar mass of the solute is ___________ $$\mathrm{g} \mathrm{~mol}^{-1}$$ (Nearest integer)

(Given : $$\mathrm{R}=0.083 \mathrm{~L} \mathrm{~bar} \mathrm{~K}^{-1} \mathrm{~mol}^{-1}$$)

JEE Main 2023 (Online) 31st January Morning Shift
25
Lead storage battery contains $38 \%$ by weight solution of $\mathrm{H}_{2} \mathrm{SO}_{4}$. The van't Hoff factor is $2.67$ at this concentration. The temperature in Kelvin at which the solution in the battery will freeze is ________. (Nearest integer).

Given $\mathrm{K}_{f}=1.8 \mathrm{~K} \mathrm{~kg} \mathrm{~mol}^{-1}$
JEE Main 2023 (Online) 30th January Evening Shift
26

A solution containing $$2 \mathrm{~g}$$ of a non-volatile solute in $$20 \mathrm{~g}$$ of water boils at $$373.52 \mathrm{~K}$$. The molecular mass of the solute is ___________ $$\mathrm{g} ~\mathrm{mol}^{-1}$$. (Nearest integer)

Given, water boils at $$373 \mathrm{~K}, \mathrm{~K}_{\mathrm{b}}$$ for water $$=0.52 \mathrm{~K} \mathrm{~kg} \mathrm{~mol}^{-1}$$

JEE Main 2023 (Online) 30th January Morning Shift
27

Solid Lead nitrate is dissolved in 1 litre of water. The solution was found to boil at 100.15$$^\circ$$C. When 0.2 mol of NaCl is added to the resulting solution, it was observed that the solution froze at $$-0.8^\circ$$ C. The solubility product of PbCl$$_2$$ formed is __________ $$\times$$ 10$$^{-6}$$ at 298 K. (Nearest integer)

Given : $$\mathrm{K_b=0.5}$$ K kg mol$$^{-1}$$ and $$\mathrm{K_f=1.8}$$ K kg mol$$^{-1}$$. Assume molality to the equal to molarity in all cases.

JEE Main 2023 (Online) 29th January Morning Shift
28

The number of pairs of the solutions having the same value of the osmotic pressure from the following is _________.

(Assume 100% ionization)

A. 0.500 $$\mathrm{M~C_2H_5OH~(aq)}$$ and 0.25 $$\mathrm{M~KBr~(aq)}$$

B. 0.100 $$\mathrm{M~K_4[Fe(CN)_6]~(aq)}$$ and 0.100 $$\mathrm{M~FeSO_4(NH_4)_2SO_4~(aq)}$$

C. 0.05 $$\mathrm{M~K_4[Fe(CN)_6]~(aq)}$$ and 0.25 $$\mathrm{M~NaCl~(aq)}$$

D. 0.15 $$\mathrm{M~NaCl~(aq)}$$ and 0.1 $$\mathrm{M~BaCl_2~(aq)}$$

E. 0.02 $$\mathrm{M~KCl.MgCl_2.6H_2O~(aq)}$$ and 0.05 $$\mathrm{M~KCl~(aq)}$$

JEE Main 2023 (Online) 25th January Evening Shift
29

The osmotic pressure of solutions of PVC in cyclohexanone at 300 K are plotted on the graph.

The molar mass of PVC is ____________ g mol$$^{-1}$$ (Nearest integer)

JEE Main 2023 (Online) 25th January Morning Shift Chemistry - Solutions Question 39 English

(Given : R = 0.083 L atm K$$^{-1}$$ mol$$^{-1}$$)

JEE Main 2023 (Online) 25th January Morning Shift
30

The total pressure observed by mixing two liquids A and B is 350 mm Hg when their mole fractions are 0.7 and 0.3 respectively.

The total pressure becomes 410 mm Hg if the mole fractions are changed to 0.2 and 0.8 respectively for A and B. The vapour pressure of pure A is __________ mm Hg. (Nearest integer)

Consider the liquids and solutions behave ideally.

JEE Main 2023 (Online) 24th January Evening Shift
31

$$1.80 \mathrm{~g}$$ of solute A was dissolved in $$62.5 \mathrm{~cm}^{3}$$ of ethanol and freezing point of the solution was found to be $$155.1 \mathrm{~K}$$. The molar mass of solute A is ________ g $$\mathrm{mol}^{-1}$$.

[Given : Freezing point of ethanol is 156.0 K.

Density of ethanol is 0.80 g cm$$-$$3.

Freezing point depression constant of ethanol is 2.00 K kg mol$$-$$1]

JEE Main 2022 (Online) 29th July Evening Shift
32

If $$\mathrm{O}_{2}$$ gas is bubbled through water at $$303 \mathrm{~K}$$, the number of millimoles of $$\mathrm{O}_{2}$$ gas that dissolve in 1 litre of water is __________. (Nearest Integer)

(Given : Henry's Law constant for $$\mathrm{O}_{2}$$ at $$303 \mathrm{~K}$$ is $$46.82 \,\mathrm{k}$$ bar and partial pressure of $$\mathrm{O}_{2}=0.920$$ bar)

(Assume solubility of $$\mathrm{O}_{2}$$ in water is too small, nearly negligible)

JEE Main 2022 (Online) 29th July Morning Shift
33

A gaseous mixture of two substances A and B, under a total pressure of $$0.8$$ atm is in equilibrium with an ideal liquid solution. The mole fraction of substance A is $$0.5$$ in the vapour phase and $$0.2$$ in the liquid phase. The vapour pressure of pure liquid $$\mathrm{A}$$ is __________ atm. (Nearest integer)

JEE Main 2022 (Online) 28th July Evening Shift
34

$$150 \mathrm{~g}$$ of acetic acid was contaminated with $$10.2 \mathrm{~g}$$ ascorbic acid $$\left(\mathrm{C}_{6} \mathrm{H}_{8} \mathrm{O}_{6}\right)$$ to lower down its freezing point by $$\left(x \times 10^{-1}\right)^{\circ} \mathrm{C}$$. The value of $$x$$ is ___________. (Nearest integer)

[Given $$\mathrm{K}_{f}=3.9 \mathrm{~K} \mathrm{~kg} \mathrm{~mol}^{-1}$$; molar mass of ascorbic acid $$=176 \mathrm{~g} \mathrm{~mol}^{-1}$$]

JEE Main 2022 (Online) 28th July Morning Shift
35

When a certain amount of solid A is dissolved in $$100 \mathrm{~g}$$ of water at $$25^{\circ} \mathrm{C}$$ to make a dilute solution, the vapour pressure of the solution is reduced to one-half of that of pure water. The vapour pressure of pure water is $$23.76 \,\mathrm{mmHg}$$. The number of moles of solute A added is _____________. (Nearest Integer)

JEE Main 2022 (Online) 27th July Evening Shift
36

The elevation in boiling point for 1 molal solution of non-volatile solute A is $$3 \mathrm{~K}$$. The depression in freezing point for 2 molal solution of $$\mathrm{A}$$ in the same solvent is 6 $$K$$. The ratio of $$K_{b}$$ and $$K_{f}$$ i.e., $$K_{b} / K_{f}$$ is $$1: X$$. The value of $$X$$ is [nearest integer]

JEE Main 2022 (Online) 26th July Evening Shift
37

Elevation in boiling point for 1.5 molal solution of glucose in water is 4 K. The depression in freezing point for 4.5 molal solution of glucose in water is 4 K. The ratio of molal elevation constant to molal depression constant (Kb/Kf) is _________.

JEE Main 2022 (Online) 29th June Evening Shift
38

1.2 mL of acetic acid is dissolved in water to make 2.0 L of solution. The depression in freezing point observed for this strength of acid is 0.0198$$^\circ$$C. The percentage of dissociation of the acid is ___________. (Nearest integer)

[Given : Density of acetic acid is 1.02 g mL$$-$$1, Molar mass of acetic acid is 60 g mol$$-$$1, Kf(H2O) = 1.85 K kg mol$$-$$1]

JEE Main 2022 (Online) 29th June Morning Shift
39

2.5 g of protein containing only glycine (C2H5NO2) is dissolved in water to make 500 mL of solution. The osmotic pressure of this solution at 300 K is found to be 5.03 $$\times$$ 10$$-$$3 bar. The total number of glycine units present in the protein is ____________.

(Given : R = 0.083 L bar K$$-$$1 mol$$-$$1)

JEE Main 2022 (Online) 28th June Evening Shift
40

The vapour pressures of two volatile liquids A and B at 25$$^\circ$$C are 50 Torr and 100 Torr, respectively. If the liquid mixture contains 0.3 mole fraction of A, then the mole fraction of liquid B in the vapour phase is $${x \over {17}}$$. The value of x is ______________.

JEE Main 2022 (Online) 28th June Morning Shift
41

A solution containing 2.5 $$\times$$ 10$$-$$3 kg of a solute dissolved in 75 $$\times$$ 10$$-$$3 kg of water boils at 373.535 K. The molar mass of the solute is ____________ g mol$$-$$1. [nearest integer] (Given : Kb(H2O) = 0.52 K kg mol$$-$$1 and boiling point of water = 373.15 K)

JEE Main 2022 (Online) 27th June Evening Shift
42

2 g of a non-volatile non-electrolyte solute is dissolved in 200 g of two different solvents A and B whose ebullioscopic constants are in the ratio of 1 : 8. The elevation in boiling points of A and B are in the ratio $${x \over y}$$ (x : y). The value of y is ______________. (Nearest integer)

JEE Main 2022 (Online) 27th June Morning Shift
43

The osmotic pressure exerted by a solution prepared by dissolving 2.0 g of protein of molar mass 60 kg mol$$-$$1 in 200 mL of water at 27$$^\circ$$C is ______________ Pa. [integer value]

(use R = 0.083 L bar mol$$-$$1 K$$-$$1)

JEE Main 2022 (Online) 26th June Evening Shift
44

A 0.5 percent solution of potassium chloride was found to freeze at $$-$$0.24$$^\circ$$C. The percentage dissociation of potassium chloride is ______________. (Nearest integer)

(Molal depression constant for water is 1.80 K kg mol$$-$$1 and molar mass of KCl is 74.6 g mol$$-$$1)

JEE Main 2022 (Online) 26th June Morning Shift
45

A company dissolves 'x' amount of CO2 at 298 K in 1 litre of water to prepare soda water. X = __________ $$\times$$ 10$$-$$3 g. (nearest integer)

(Given : partial pressure of CO2 at 298 K = 0.835 bar.

Henry's law constant for CO2 at 298 K = 1.67 kbar.

Atomic mass of H, C and O is 1, 12, and 6 g mol$$-$$1, respectively)

JEE Main 2022 (Online) 24th June Evening Shift
46

The osmotic pressure of blood is 7.47 bar at 300 K. To inject glucose to a patient intravenously, it has to be isotonic with blood. The concentration of glucose solution in gL$$-$$1 is _____________.

(Molar mass of glucose = 180 g mol$$-$$1, R = 0.083 L bar K$$-$$1 mol$$-$$1) (Nearest integer)

JEE Main 2022 (Online) 24th June Morning Shift
47
1.22 g of an organic acid is separately dissolved in 100 g of benzene (Kb = 2.6 K kg mol$$-$$1) and 100 g of acetone (Kb = 1.7 K kg mol$$-$$1). The acid is known to dimerize in benzene but remain as a monomer in acetone. The boiling point of the solution in acetone increases by 0.17$$^\circ$$C. The increase in boiling point of solution in benzene in $$^\circ$$C is x $$\times$$ 10$$-$$2. The value of x is ______________. (Nearest integer) [Atomic mass : C = 12.0, H = 1.0, O =16.0]
JEE Main 2021 (Online) 31st August Evening Shift
48
40 g of glucose (Molar mass = 180) is mixed with 200 mL of water. The freezing point of solution is __________ K. (Nearest integer) [Given : Kf = 1.86 K kg mol$$-$$1; Density of water = 1.00 g cm$$-$$3; Freezing point of water = 273.15 K]
JEE Main 2021 (Online) 27th August Evening Shift
49
1 kg of 0.75 molal aqueous solution of sucrose can be cooled up to $$-$$4$$^\circ$$C before freezing. The amount of ice (in g) that will be separated out is __________. (Nearest integer)

[Given : Kf(H2O) = 1.86 K kg mol$$-$$1]
JEE Main 2021 (Online) 27th August Morning Shift
50
83 g of ethylene glycol dissolved in 625 g of water. The freezing point of the solution is ____________ K. (Nearest integer)

[Use : Molal Freezing point depression constant of water = 1.86 K kg mol$$-$$1]

Freezing Point of water = 273 K

Atomic masses : C : 12.0 u, O : 16.0 u, H : 1.0 u]
JEE Main 2021 (Online) 26th August Evening Shift
51
Of the following four aqueous solutions, total number of those solutions whose freezing point is lower than that of 0.10 M C2H5OH is __________ (Integer answer)

(i) 0.10 M Ba3(PO4)2

(ii) 0.10 M Na2SO4

(iii) 0.10 M KCl

(iv) 0.10 M Li3PO4
JEE Main 2021 (Online) 26th August Morning Shift
52
In a solvent 50% of an acid HA dimerizes and the rest dissociates. The van't Hoff factor of the acid is __________ $$\times$$ 10$$-$$2.

(Round off to the nearest integer)
JEE Main 2021 (Online) 27th July Evening Shift
53
1.46 g of a biopolymer dissolved in a 100 mL water at 300 K exerted an osmotic pressure of 2.42 $$\times$$ 10$$-$$3 bar.

The molar mass of the biopolymer is _____________ $$\times$$ 104 g mol$$-$$1. (Round off to the Nearest Integer)

[Use : R = 0.083 L bar mol$$-$$1 K$$-$$1]
JEE Main 2021 (Online) 27th July Morning Shift
54
When 3.00 g of a substance 'X' is dissolved in 100 g of CCl4, it raises the boiling point by 0.60 K. The molar mass of the substance 'X' is ______________ g mol$$-$$1. (Nearest integer).

[Given Kb for CCl4 is 5.0 K kg mol$$-$$1]
JEE Main 2021 (Online) 25th July Evening Shift
55
CO2 gas is bubbled through water during a soft drink manufacturing process at 298 K. If CO2 exerts a partial pressure of 0.835 bar then x m mol of CO2 would dissolve in 0.9 L of water. The value of x is ____________. (Nearest integer)

(Henry's law constant for CO2 at 298 K is 1.67 $$\times$$ 103 bar)
JEE Main 2021 (Online) 25th July Morning Shift
56
The vapour pressures of A and B at 25$$^\circ$$C are 90 mm Hg and 15 mm Hg respectively. If A and B are mixed such that the mole fraction of A in the mixture is 0.6, then the mole fraction of B in the vapour phase is x $$\times$$ 10$$-$$1. The value of x is ___________. (Nearest integer)
JEE Main 2021 (Online) 20th July Evening Shift
57
At 20$$^\circ$$ C, the vapour pressure of benzene is 70 torr and that of methyl benzene is 20 torr. The mole fraction of benzene in the vapour phase at 20$$^\circ$$ above an equimolar mixture of benzene and methyl benzene is _____________ $$\times$$ 10$$-$$2. (Nearest integer)
JEE Main 2021 (Online) 20th July Morning Shift
58
A solute A dimerizes in water. The boiling point of a 2 molal solution of A is 100.52$$^\circ$$C. The percentage association of A is __________. (Round off to the Nearest Integer).

[Use : Kb for water = 0.52 K kg mol$$-$$1 Boiling point of water = 100$$^\circ$$C]
JEE Main 2021 (Online) 18th March Evening Shift
59
2 molal solution of a weak acid HA has a freezing point of 3.885$$^\circ$$C. The degree of dissociation of this acid is ___________ $$\times$$ 10$$-$$3. (Round off to the Nearest Integer).

[Given : Molal depression constant of water = 1.85 K kg mol$$-$$1 Freezing point of pure water = 0$$^\circ$$ C]
JEE Main 2021 (Online) 18th March Morning Shift
60
A 1 molal K4Fe(CN)6 solution has a degree of dissociation of 0.4. Its boiling point is equal to that of another solution which contains 18.1 weight percent of a non electrolytic solute A. The molar mass of A is __________ u. (Round off to the Nearest Integer). [Density of water = 1.0 g cm$$-$$3 ]
JEE Main 2021 (Online) 17th March Evening Shift
61
The oxygen dissolved in water exerts a partial pressure of 20 kPa in the vapour above water. The molar solubility of oxygen in water is __________ $$\times$$ 10$$-$$5 mol dm$$-$$3. (Round off to the Nearest Integer).

[Given : Henry's law constant = KH = 8.0 $$\times$$ 104 kPa for O2. Density of water with dissolved oxygen = 1.0 kg dm$$-$$3 ]
JEE Main 2021 (Online) 17th March Morning Shift
62
At 363 K, the vapour pressure of A is 21 kPa and that of B is 18 kPa. One mole of A and 2 moles of B are mixed. Assuming that this solution is ideal, the vapour pressure of the mixture is ___________ kPa. (Round off to the Nearest Integer).
JEE Main 2021 (Online) 16th March Evening Shift
63
AB2 is 10% dissociated in water to A2+ and B$$-$$. The boiling point of a 10.0 molal aqueous solution of AB2 is __________$$^\circ$$C. (Round off to the Nearest Integer).

[Given : Molal elevation constant of water Kb = 0.5 K kg mol$$-$$1 boiling point of pure water = 100$$^\circ$$C]
JEE Main 2021 (Online) 16th March Morning Shift
64
When 12.2 g of benzoic acid is dissolved in 100 g of water, the freezing point of solution was found to be $$-$$0.93$$^\circ$$C (Kf(H2O) = 1.86 K kg mol$$-$$1). The number (n) of benzoic acid molecules associated (assuming 100% association) is ___________.
JEE Main 2021 (Online) 26th February Evening Shift
65
224 mL of SO2(g) at 298 K and 1 atm is passed through 100 mL of 0.1 M NaOH solution. The non-volatile solute produced is dissolved in 36g of water. The lowering of vapour pressure of solution (assuming the solution in dilute) (P$$_{({H_2}O)}^o$$ $$-$$ 24 mm of Hg) is x $$\times$$ 10$$-$$2 mm of Hg, the value of x is ___________. (Integer answer)
JEE Main 2021 (Online) 26th February Morning Shift
66
If a compound AB dissociates to the extent of 75% in an aqueous solution, the molality of the solution which shows a 2.5 K rise in the boiling point of the solution is ____________ molal. (Rounded off to the nearest integer)

[Kb = 0.52 K kg mol$$-$$1]
JEE Main 2021 (Online) 25th February Evening Shift
67
1 molal aqueous solution of an electrolyte A2B3 is 60% ionised. The boiling point of the solution at 1 atm is _________ K. (Rounded off to the nearest integer)

[Given Kb for (H2O) = 0.52 K kg mol$$-$$1]
JEE Main 2021 (Online) 25th February Morning Shift
68
C6H6 freezes at 5.5$$^\circ$$C. The temperature at which a solution of 10g of C4H10 in 200g of C6H6 freeze is __________ $$^\circ$$C. (The molal freezing point depression constant of C6H6 is 5.12$$^\circ$$C/m.)
JEE Main 2021 (Online) 24th February Evening Shift
69
When 9.45 g of CICH2COOH is added to 500 mL of water, its freezing point drops by 0.5°C. The dissociation constant of CICH2COOH is x $$ \times $$ 10-3.
The value of x is ________. (Rounded off to the nearest integer)
[Kf(H20) = 1.86 K kg mol-1]
JEE Main 2021 (Online) 24th February Morning Shift
70
The elevation of boiling point of 0.10 m aqueous CrCl3.xNH3 solution is two times that of 0.05 m aqueous CaCl2 solution. The value of x is ______.

[Assume 100% ionisation of the complex and CaCl2, coordination number of Cr as 6, and that all NH3 molecules are present inside the coordination sphere]
JEE Main 2020 (Online) 6th September Morning Slot
71
The osmotic pressure of a solution of NaCl is 0.10 atm and that of a glucose solution is 0.20 atm. The osmotic pressure of a solution formed by mixing 1 L of the sodium chloride solution with 2 L of
the glucose solution is x $$ \times $$ 10–3 atm. x is _____. (nearest integer)
JEE Main 2020 (Online) 4th September Evening Slot
72
At 300 K, the vapour pressure of a solution containing 1 mole of n-hexane and 3 moles of n-heptane is 550 mm of Hg. At the same temperature, if one more mole of n-heptane is added to this solution, the vapour pressure of the solution increases by 10 mm of Hg. What is the vapour pressure in mm Hg of n-heptane in its pure state ______?
JEE Main 2020 (Online) 4th September Morning Slot
73
If 250 cm3 of an aqueous solution containing 0.73 g of a protein A is isotonic with one litre of another aqueous solution containing 1.65 g of a protein B, at 298 K, the ratio of the molecular masses of A and B is ______ × 10–2 (to the nearest integer).
JEE Main 2020 (Online) 3rd September Evening Slot
74
A cylinder containing an ideal gas (0.1 mol of 1.0 dm3) is in thermal equilibrium with a large volume of 0.5 molal aqueous solution of ethylene glycol at its freezing point. If the stoppers S1 and S2 (as shown in the figure) are suddenly withdrawn, the volume of the gas in litres after equilibrium is achieved will be____.

(Given, Kf (water) = 2.0 K kg mol–1,
R = 0.08 dm3 atm K–1 mol–1)

JEE Main 2020 (Online) 9th January Evening Slot Chemistry - Solutions Question 103 English
JEE Main 2020 (Online) 9th January Evening Slot
75
How much amount of NaCl should be added to 600 g of water ($$\rho $$ = 1.00 g/mL) to decrease the freezing point of water to – 0.2 °C ? ______.
(The freezing point depression constant for water = 2K kg mol–1)
JEE Main 2020 (Online) 9th January Morning Slot

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