Chemical Kinetics and Nuclear Chemistry · Chemistry · JEE Main

Start Practice

MCQ (Single Correct Answer)

1

In a first order decomposition reaction, the time taken for the decomposition of reactant to one fourth and one eighth of its initial concentration are $t_1$ and $t_2$ (s), respectively. The ratio $t_1/t_2$ will be:

JEE Main 2025 (Online) 8th April Evening Shift
2

A(g) → B(g) + C(g) is a first order reaction.

Time t
Psystem Pt P

The reaction was started with reactant A only. Which of the following expressions is correct for rate constant k?

JEE Main 2025 (Online) 7th April Evening Shift
3

A person's wound was exposed to some bacteria and then bacterial growth started to happen at the same place. The wound was later treated with some antibacterial medicine and the rate of bacterial decay(r) was found to be proportional with the square of the existing number of bacteria at any instance. Which of the following set of graphs correctly represents the 'before' and 'after' situation of the application of the medicine?

[Given: $N=$ No. of bacteria, $t=$ time, bacterial growth follows $1^{\text {st }}$ order kinetics.]

JEE Main 2025 (Online) 7th April Morning Shift
4

Reaction $\mathrm{A}(\mathrm{g}) \rightarrow 2 \mathrm{~B}(\mathrm{~g})+\mathrm{C}(\mathrm{g})$ is a first order reaction. It was started with pure A

t/min Pressure of system at time t/mm Hg
10 160
$\infty$ 240

Which of the following option is incorrect?

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

Consider the following plots of $\log$ of rate constant $\mathrm{k}(\log \mathrm{k})$ vs $\frac{1}{\mathrm{~T}}$ for three different reactions. The correct order of activation energies of these reactions is :

JEE Main 2025 (Online) 4th April Evening Shift Chemistry - Chemical Kinetics and Nuclear Chemistry Question 5 English

JEE Main 2025 (Online) 4th April Evening Shift
6

Half life of zero order reaction $\mathrm{A} \rightarrow$ product is 1 hour, when initial concentration of reactant is $2.0 \mathrm{~mol} \mathrm{~L}{ }^{-1}$. The time required to decrease concentration of A from 0.50 to $0.25 \mathrm{~mol} \mathrm{~L}^{-1}$ is :

JEE Main 2025 (Online) 4th April Evening Shift
7

For $\mathrm{A}_2+\mathrm{B}_2 \rightleftharpoons 2 \mathrm{AB}$

$\mathrm{E}_{\mathrm{a}}$ for forward and backward reaction are 180 and $200 \mathrm{~kJ} \mathrm{~mol}^{-1}$ respectively

If catalyst lowers $\mathrm{E}_{\mathrm{a}}$ for both reaction by $100 \mathrm{~kJ} \mathrm{~mol}^{-1}$.

Which of the following statement is correct?

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

Rate law for a reaction between $A$ and $B$ is given by

$$\mathrm{r}=\mathrm{k}[\mathrm{~A}]^{\mathrm{n}}[\mathrm{~B}]^{\mathrm{m}}$$

If concentration of $A$ is doubled and concentration of $B$ is halved from their initial value, the ratio of new rate of reaction to the initial rate of reaction $\left(\frac{r_2}{r_1}\right)$ is

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

Consider the following statements related to temperature dependence of rate constants.

Identify the correct statements.

A. The Arrhenius equation holds true only for an elementary homogenous reaction.

B. The unit of $A$ is same as that of $k$ in Arrhenius equation.

C. At a given temperature, a low activation energy means a fast reaction.

D. A and Ea as used in Arrhenius equation depend on temperature.

E. When $\mathrm{Ea} \gg \mathrm{RT}, \mathrm{A}$ and Ea become interdependent.

Choose the correct answer from the options given below:

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

In a reaction $A+B \rightarrow C$, initial concentrations of $A$ and $B$ are related as $[A]_0=8[B]_0$. The half lives of $A$ and $B$ are 10 min and 40 min , respectively. If they start to disappear at the same time, both following first order kinetics, after how much time will the concentration of both the reactants be same?

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

Reactant A converts to product D through the given mechanism (with the net evolution of heat):

A → B     slow;     ΔH = +ve

B → C     fast;     ΔH = -ve

C → D     fast;     ΔH = -ve

Which of the following represents the above reaction mechanism?

JEE Main 2025 (Online) 2nd April Evening Shift
12

Drug $X$ becomes ineffective after $50 \%$ decomposition. The original concentration of drug in a bottle was $16 \mathrm{mg} / \mathrm{mL}$ which becomes $4 \mathrm{mg} / \mathrm{mL}$ in 12 months. The expiry time of the drug in months is _________.

Assume that the decomposition of the drug follows first order kinetics.

JEE Main 2025 (Online) 29th January Evening Shift
13

The reaction $A_2 + B_2 \rightarrow 2AB$ follows the mechanism:

$A_2 \overset{k_1}{\underset{k_{-1}}{\rightleftharpoons}} A + A$ (fast)

$A + B_2 \xrightarrow{k_2} AB + B$ (slow)

$A + B \rightarrow AB$ (fast)

The overall order of the reaction is:

JEE Main 2025 (Online) 29th January Morning Shift
14

Consider an elementary reaction

$$ \mathrm{A}(\mathrm{~g})+\mathrm{B}(\mathrm{~g}) \rightarrow \mathrm{C}(\mathrm{~g})+\mathrm{D}(\mathrm{~g}) $$

If the volume of reaction mixture is suddenly reduced to $\frac{1}{3}$ of its initial volume, the reaction rate will become ' $x^{\prime}$ times of the original reaction rate. The value of $x$ is :

JEE Main 2025 (Online) 28th January Evening Shift
15

For bacterial growth in a cell culture, growth law is very similar to the law of radioactive decay. Which of the following graphs is most suitable to represent bacterial colony growth ?

Where N - Number of Bacteria at any time, $\mathrm{N}_0$ - Initial number of Bacteria.

JEE Main 2025 (Online) 28th January Evening Shift
16

JEE Main 2025 (Online) 28th January Morning Shift Chemistry - Chemical Kinetics and Nuclear Chemistry Question 14 English

For a given reaction $\mathrm{R} \rightarrow \mathrm{P}, \mathrm{t}_{1 / 2}$ is related to $[\mathrm{A}]_0$ as given in table.

Given: $\log 2=0.30$

Which of the following is true?

A. The order of the reaction is $1 / 2$.

B. If $[\mathrm{A}]_0$ is 1 M , then $\mathrm{t}_{1 / 2}$ is $200 \sqrt{10} \mathrm{~min}$

C. The order of the reaction changes to 1 if the concentration of reactant changes from 0.100 M to 0.500 M.

D. $\mathrm{t}_{1 / 2}$ is 800 min for $[\mathrm{A}]_0=1.6 \mathrm{M}$

Choose the correct answer from the options given below:

JEE Main 2025 (Online) 28th January Morning Shift
17

Given below are two statements :

Statement (I) : JEE Main 2025 (Online) 24th January Evening Shift Chemistry - Chemical Kinetics and Nuclear Chemistry Question 15 English 1 is valid for first order reaction.

Statement (II) : JEE Main 2025 (Online) 24th January Evening Shift Chemistry - Chemical Kinetics and Nuclear Chemistry Question 15 English 2 is valid for first order reaction.

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

JEE Main 2025 (Online) 24th January Evening Shift
18

For a reaction, $\mathrm{N}_2 \mathrm{O}_{5(\mathrm{~g})} \rightarrow 2 \mathrm{NO}_{2(\mathrm{~g})}+\frac{1}{2} \mathrm{O}_{2(\mathrm{~g})}$ in a constant volume container, no products were present initially. The final pressure of the system when $50 \%$ of reaction gets completed is

JEE Main 2025 (Online) 24th January Morning Shift
19

Which of the following graphs most appropriately represents a zero order reaction?

JEE Main 2025 (Online) 23rd January Evening Shift
20

Consider the given figure and choose the correct option :

JEE Main 2025 (Online) 22nd January Evening Shift Chemistry - Chemical Kinetics and Nuclear Chemistry Question 20 English

JEE Main 2025 (Online) 22nd January Evening Shift
21

Which of the following statement is not true for radioactive decay?

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

For a reaction $$A \xrightarrow{\mathrm{K}_1} \mathrm{~B} \xrightarrow{\mathrm{K}_2} \mathrm{C}$$ If the rate of formation of B is set to be zero then the concentration of B is given by :

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

Integrated rate law equation for a first order gas phase reaction is given by (where $$\mathrm{P}_{\mathrm{i}}$$ is initial pressure and $$\mathrm{P}_{\mathrm{t}}$$ is total pressure at time $$t$$)

JEE Main 2024 (Online) 31st January Morning Shift
24

For a chemical reaction $$\mathrm{A}+\mathrm{B} \rightarrow$$ Product, the order is 1 with respect to $$\mathrm{A}$$ and $$\mathrm{B}$$.

$$\mathrm{Rate}$$
$$\mathrm{mol~L^{-1}~S^{-1}}$$
$$\mathrm{[A]}$$
$$\mathrm{mol~L^{-1}}$$
$$\mathrm{[B]}$$
$$\mathrm{mol~L^{-1}}$$
0.10 20 0.5
0.40 $$x$$ 0.5
0.80 40 $$y$$

What is the value of $$x$$ and $$y$$ ?

JEE Main 2023 (Online) 11th April Evening Shift
25

The correct reaction profile diagram for a positive catalyst reaction.

JEE Main 2023 (Online) 8th April Evening Shift
26

Consider the following reaction that goes from A to B in three steps as shown below:

JEE Main 2023 (Online) 6th April Evening Shift Chemistry - Chemical Kinetics and Nuclear Chemistry Question 47 English

Choose the correct option

JEE Main 2023 (Online) 6th April Evening Shift
27

A student has studied the decomposition of a gas AB$$_3$$ at 25$$^\circ$$C. He obtained the following data.

p (mm Hg) 50 100 200 400
relative t$$_{1/2}$$ (s) 4 2 1 0.5

The order of the reaction is

JEE Main 2023 (Online) 24th January Evening Shift
28

For kinetic study of the reaction of iodide ion with $$\mathrm{H}_{2} \mathrm{O}_{2}$$ at room temperature :

(A) Always use freshly prepared starch solution.

(B) Always keep the concentration of sodium thiosulphate solution less than that of KI solution.

(C) Record the time immediately after the appearance of blue colour.

(D) Record the time immediately before the appearance of blue colour.

(E) Always keep the concentration of sodium thiosulphate solution more than that of KI solution.

Choose the correct answer from the options given below :

JEE Main 2022 (Online) 28th July Morning Shift
29

At $$30^{\circ} \mathrm{C}$$, the half life for the decomposition of $$\mathrm{AB}_{2}$$ is $$200 \mathrm{~s}$$ and is independent of the initial concentration of $$\mathrm{AB}_{2}$$. The time required for $$80 \%$$ of the $$\mathrm{AB}_{2}$$ to decompose is

Given: $$\log 2=0.30$$ $$\quad \log 3=0.48$$

JEE Main 2022 (Online) 26th July Evening Shift
30

For a first order reaction, the time required for completion of 90% reaction is 'x' times the half life of the reaction. The value of 'x' is

(Given : ln 10 = 2.303 and log 2 = 0.3010)

JEE Main 2022 (Online) 24th June Evening Shift
31
Which one of the following given graphs represents the variation of rate constant (k) with temperature (T) for an endothermic reaction?
JEE Main 2021 (Online) 1st September Evening Shift
32
For a reaction of order n, the unit of the rate constant is :
JEE Main 2021 (Online) 27th July Morning Shift
33
For the following graphs,

JEE Main 2021 (Online) 25th July Morning Shift Chemistry - Chemical Kinetics and Nuclear Chemistry Question 104 English
Choose from the options given below, the correct one regarding order of reaction is :
JEE Main 2021 (Online) 25th July Morning Shift
34
Isotope(s) of hydrogen which emits low energy $$\beta$$$$-$$ particles with t1/2 value > 12 years is/are
JEE Main 2021 (Online) 22th July Evening Shift
35
Consider the following reactions

A $$ \to $$ P1 ; B $$ \to $$ P2 ; C $$ \to $$ P3 ; D $$ \to $$ P4,

The order of the above reactions are a, b, c, and d, respectively. The following graph is obtained when log[rate] vs. log[conc.] are plotted JEE Main 2020 (Online) 6th September Morning Slot Chemistry - Chemical Kinetics and Nuclear Chemistry Question 121 English
Among the following, the correct sequence for the order of the reactions is :
JEE Main 2020 (Online) 6th September Morning Slot
36
The rate constant (k) of a reaction is measured at differenct temperatures (T), and the data are plotted in the given figure. The activation energy of the reaction in kJ mol–1 is :
(R is gas constant) JEE Main 2020 (Online) 5th September Evening Slot Chemistry - Chemical Kinetics and Nuclear Chemistry Question 122 English
JEE Main 2020 (Online) 5th September Evening Slot
37
A flask contains a mixture of compounds A and B. Both compounds decompose by first-order kinetics. The half-lives for A and B are 300 s and 180 s, respectively. If the concentrations of A and B are equal initially, the time required for the concentration of A to be four times that of B(in s) :
(Use ln 2 = 0.693)
JEE Main 2020 (Online) 5th September Morning Slot
38
For the reaction
2A + 3B + $${3 \over 2}$$C $$ \to $$ 3P, which statement is correct ?
JEE Main 2020 (Online) 3rd September Evening Slot
39
It is true that :
JEE Main 2020 (Online) 3rd September Morning Slot
40
The results given in the below table were obtained during kinetic studies of the following reaction

2A + B $$ \to $$ C + D JEE Main 2020 (Online) 2nd September Evening Slot Chemistry - Chemical Kinetics and Nuclear Chemistry Question 128 English
X and Y in the given table are respectively :
JEE Main 2020 (Online) 2nd September Evening Slot
41
For the following reactions
$$A\buildrel {700K} \over \longrightarrow {\mathop{\rm Product}\nolimits} $$
$$A\mathrel{\mathop{\kern0pt\longrightarrow} \limits_{catalyst}^{500K}} {\mathop{\rm Product}\nolimits} $$
it was found that Ea is decreased by 30 kJ/mol in the presence of catalyst.
If the rate remains unchanged, the activation energy for catalysed reaction is (Assume pre exponential factor is same):
JEE Main 2020 (Online) 9th January Morning Slot
42
Consider the following plots of rate constant versus $${1 \over T}$$ for four different reactions. Which of the following orders is correct for the activation energies of these reactions?

JEE Main 2020 (Online) 8th January Evening Slot Chemistry - Chemical Kinetics and Nuclear Chemistry Question 131 English
JEE Main 2020 (Online) 8th January Evening Slot
43
The rate of a certain biochemical reaction at physiological temperature (T) occurs 106 times faster with enzyme than without. The change in the activation energy upon adding enzyme is :
JEE Main 2020 (Online) 8th January Morning Slot
44
For the reaction
2H2(g) + 2NO(g) $$ \to $$ N2(g) + 2H2O(g)
the observed rate expression is, rate = Kf[NO]2[H2]. The rate expression for the reverse reaction is :
JEE Main 2020 (Online) 7th January Evening Slot
45
NO2 required for a reaction is produced by the decomposition of N2O5 in CCl4 as per the equation,
2N2O5(g) $$ \to $$ 4NO2(g) + O2(g).
The initial concentration of N2O5 is 3.00 mol L–1 and it is 2.75 mol L–1 after 30 minutes. The rate of formation of NO2 is :
JEE Main 2019 (Online) 12th April Evening Slot
46
In the following reaction; xA $$ \to $$ yB
$${\log _{10}}\left[ { - {{d\left[ A \right]} \over {dt}}} \right] = {\log _{10}}\left[ {{{d\left[ B \right]} \over {dt}}} \right] + 0.3010$$
'A' and 'B' respectively can be :
JEE Main 2019 (Online) 12th April Morning Slot
47
For the reaction of H2 with I2, the rate constant is 2.5 × 10–4 dm3 mol–1s–1 at 327°C and 1.0 dm3 mol–1 at 527°C. The activation energy for the reaction, in kJ mole–1 is : (R = 8.314 JK–1 mol–1 )
JEE Main 2019 (Online) 10th April Evening Slot
48
A bacterial infection in an internal wound grows as N'(t) = N0 exp(t), where the time t is in hours. A does of antibiotic, taken orally, needs 1 hour to reach the wound. Once it reaches there, the bacterial population goes down as $${{dN} \over {dt}} = - 5{N^2}$$. What will be the plot of $${{{N_0}} \over N}$$ vs. t after 1 hour?
JEE Main 2019 (Online) 10th April Morning Slot
49
Consider the given plot of enthalpy of the following reaction between A and B.
A+ B $$ \to $$ C + D
Identify the incorrect statement. JEE Main 2019 (Online) 9th April Evening Slot Chemistry - Chemical Kinetics and Nuclear Chemistry Question 139 English
JEE Main 2019 (Online) 9th April Evening Slot
50
The given plots represent the variation of the concentration of a reactant R with time for two different reactions (i) and (ii). The respective orders of the reactions are : JEE Main 2019 (Online) 9th April Morning Slot Chemistry - Chemical Kinetics and Nuclear Chemistry Question 140 English
JEE Main 2019 (Online) 9th April Morning Slot
51
For a reaction scheme $$A\buildrel {{k_1}} \over \longrightarrow B\buildrel {{k_2}} \over \longrightarrow C$$,

if the rate of formation of B is set to be zero then the concentration of B is given by :
JEE Main 2019 (Online) 8th April Evening Slot
52
For the reaction 2A + B $$ \to $$ C, the values of initial rate at diffrent reactant concentrations are given in the table below. The rate law for the reaction is :

[A] (mol L-1) [B] (mol L-1) Initial Rate (mol L-1s-1)
0.05 0.05 0.045
0.10 0.05 0.090
0.20 0.10 0.72
JEE Main 2019 (Online) 8th April Morning Slot
53
For a reaction consider the plot of $$\ell $$n k versus 1/T given in the figure. If the rate constant of this reaction at 400 K is 10–5 s–1, then the rate constant at 500 K is –

JEE Main 2019 (Online) 12th January Evening Slot Chemistry - Chemical Kinetics and Nuclear Chemistry Question 143 English
JEE Main 2019 (Online) 12th January Evening Slot
54
Decomposition of X exhibits a rate constant of 0.05 $$\mu $$g/year. How many year are required for the decomposition of 5$$\mu $$g of X into 2.5 $$\mu $$g?
JEE Main 2019 (Online) 12th January Morning Slot
55
The reaction 2X $$ \to $$ B is a zeroth order reaction. If the initial concentration of X is 0.2 M, the half-life is 6 h. When the initial concentration of X is 0.5 M, the time required to reach its final concentration of 0.2 M will be:
JEE Main 2019 (Online) 11th January Evening Slot
56
If a reaction follows the Arrhenius equation, the plot ln k vs $${1 \over {\left( {RT} \right)}}$$ gives straight line with a gradient ($$-$$ y) unit.

The energy required to active the reactant is :
JEE Main 2019 (Online) 11th January Morning Slot
57
For an elementary chemical reaction,

JEE Main 2019 (Online) 10th January Evening Slot Chemistry - Chemical Kinetics and Nuclear Chemistry Question 147 English

the expression for $${{d\left[ A \right]} \over {dt}}$$ is
JEE Main 2019 (Online) 10th January Evening Slot
58
Consider the given plots for a reaction obeying Arrhenius equation (0oC < T < 300oC) : (K and Ea are rate constant and activation energy, respectively)

JEE Main 2019 (Online) 10th January Morning Slot Chemistry - Chemical Kinetics and Nuclear Chemistry Question 148 English

Choose the correct option :
JEE Main 2019 (Online) 10th January Morning Slot
59
For the reaction, 2A + B $$ \to $$ products, when the concentrations of A and B both were doubled, the rate of the reaction increased from 0.3 mol L$$-$$1s$$-$$1 to 2.4 mol L$$-$$1s$$-$$1. When the concentration of A alone is doubled, the rate increased from 0.3 mol L$$-$$1s$$-$$1 to 0.6 mol L$$-$$1s$$-$$1.
JEE Main 2019 (Online) 9th January Evening Slot
60
The following results were obtained during kinetic studies of the reaction ;

2A + B $$ \to $$ Products

Experiment [A] (in mol L$$-$$1) [b] (in mol L$$-$$1) Initial Rate of reaction
(In mol L$$-$$1 min$$-$$1)
I 0.10 0.20 6.93 G 10$$-$$3
II 0.10 0.25 6.93 G 10$$-$$3
III 0.20 0.30 1.386 G 10$$-$$2


The time (in minutes) required to consume half of A is :
JEE Main 2019 (Online) 9th January Morning Slot
61
If 50% of a reaction occurs in 100 second and 75% of the reaction occurs in 200 secod, the order of this reaction is :
JEE Main 2018 (Online) 16th April Morning Slot
62
At 518oC the rate of decomposition of a sample of gaseous acetaldehyde initially at a pressure of 363 Torr, was 1.00 Torr s–1 when 5% had reacted and 0.5 Torr s–1 when 33% had reacted. The order of the reaction is
JEE Main 2018 (Offline)
63
For a first order reaction, A $$ \to $$ P, t1/2 (half-life) is 10 days The time required for $${1 \over 4}$$th conversion of A (in days) is : (ln 2 = 0.693,    ln 3 = 1.1)
JEE Main 2018 (Online) 15th April Evening Slot
64
N2O5 decomposes to NO2 and O2 and follows first order kinetics. After 50 minutes, the pressure inside the vessel increases from 50 mmHg to 87.5 mmHg. The pressure of the gaseous mixture after 100 minute at constant temperature will be :
JEE Main 2018 (Online) 15th April Morning Slot
65
The rate of a reaction quadruples when the temperature changes from 300 to 310 K. The activation energy of this reaction is :

(Assume activation energy and preexponential factor are independent of temperature; ln 2 = 0.693; R = 8.314 J mol−1 K−1)
JEE Main 2017 (Online) 9th April Morning Slot
66
The rate of a reaction A doubles on increasing the temperature from 300 to 310 K. By how much, the temperature of reaction B should be Increased from 300 K so that rate doubles if activation energy of the reaction B is twice to that of reaction A.
JEE Main 2017 (Online) 8th April Morning Slot
67
Two reactions R1 and R2 have identical pre-exponential factors. Activation energy of R1 exceeds that of R2 by 10 kJ mol–1. If k1 and k2 are rate constants for reactions R1 and R2 respectively at 300 K, then ln(k2/k1) is equal to :
(R = 8.314 J mol–1 K–1)
JEE Main 2017 (Offline)
68
The rate law for the reaction below is given by the expression k [A] [B]

A + B $$ \to $$ Product

If the concentration of B is increased from 0.1 to 0.3 mole, keeping the value of A at 0.1 mole, the rate constant will be :
JEE Main 2016 (Online) 10th April Morning Slot
69
The reaction of ozone with oxygen atoms in the presence of chlorine atoms can occur by a two step process shown below :

O3(g) + Cl$${^ \bullet }$$ (g) $$ \to $$ O2(g) + ClO$${^ \bullet }$$ (g) . . . . . .(i)

ki = 5.2 × 109 L mol−1 s−1

ClO$${^ \bullet }$$(g) + O$${^ \bullet }$$(g) $$ \to $$ O2(g) + Cl$${^ \bullet }$$ (g) . . . . . . (ii)

kii = 2.6 × 1010 L mol−1 s−1

The closest rate constant for the overall reaction O3(g) + O$${^ \bullet }$$ (g) $$ \to $$ 2 O2(g) is :
JEE Main 2016 (Online) 9th April Morning Slot
70
Decomposition of H2O2 follows a first order reaction. In fifty minutes the concentration of H2O2 decreases from 0.5 to 0.125 M in one such decomposition. When the concentration of H2O2 reaches 0.05 M, the rate of formation of O2 will be :
JEE Main 2016 (Offline)
71
Higher order (>3) reactions are rare due to
JEE Main 2015 (Offline)
72
For the non – stoichiometre reaction 2A + B $$\to$$ C + D, the following kinetic data were obtained in three separate experiments, all at 298 K.
Initial Concentration (A) Initial Concentration (B) Initial rate of formation of C (mol L-1 s-1)
0.1 M 0.1 M 1.2 x 10-3
0.1 M 0.2 M 1.2 x 10-3
0.2 M 0.1 M 2.4 x 10-3
The rate law for the formation of C is:
JEE Main 2014 (Offline)
73
The rate of a reaction doubles when its temperature changes from 300K to 310K. Activation energy of such a reaction will be:(R = 8.314 JK–1 mol–1 and log 2 = 0.301)
JEE Main 2013 (Offline)
74
For a first order reaction, (A) $$\to$$ products, the concentration of A changes from 0.1 M to 0.025 M in 40 minutes. The rate of reaction when the concentration of A is 0.01 M is :
AIEEE 2012
75
The rate of a chemical reaction doubles for every 10oC rise of temperature. If the temperature is raised by 50oC , the rate of the reaction increases by about :
AIEEE 2011
76
The time for half life period of a certain reaction A $$\to$$ products is 1 hour. When the initial concentration of the reactant ‘A’, is 2.0 mol L–1, how much time does it take for its concentration to come from 0.50 to 0.25 mol L–1 if it is a zero order reaction ?
AIEEE 2010
77

Consider the reaction :

Cl2(aq) + H2S(aq) → S(s) + 2H+ (aq) + 2Cl (aq)

The rate equation for this reaction is rate = k [Cl2] [H2S]

Which of these mechanisms is/are consistent with this rate equation?

(A) Cl2 + H2S $$\to$$ H+ + Cl + Cl+ + HS (slow)

Cl+ + HS $$\to$$ H+ + Cl + S (fast)

(B) H2S $$ \Leftrightarrow $$ H+ + HS (fast equilibrium)

Cl2 + HS $$\to$$ 2Cl + H+ + S (slow)

AIEEE 2010
78
The half life period of a first order chemical reaction is 6.93 minutes. The time required for the completion of 99% of the chemical reaction will be (log 2=0.301) :
AIEEE 2009
79
For a reaction $${1 \over 2}A \to 2B$$ rate of disappearance of ‘A’ is related to the rate of appearance of ‘B’ by the expression
AIEEE 2008
80
The energies of activation for forward and reverse reactions for A2 + B2 $$\leftrightharpoons$$ 2AB are 180 kJ mol−1 and 200 kJ mol−1 respectively. The presence of catalyst lowers the activation energy of both (forward and reverse) reactions by 100 kJ mol−1. The enthalpy change of the reaction ( A2 + B2 $$\to$$ 2AB) in the presence of catalyst will be (in kJ mol−1)
AIEEE 2007
81
Consider the reaction, 2A + B $$\to$$ products. When concentration of B alone was doubled, the half-life did not change. When the concentration of A alone was doubled, the rate increased by two times. The unit of rate constant for this reaction is
AIEEE 2007
82
A radioactive element gets spilled over the floor of a room. Its half-life period is 30 days. If the initial activity is ten times the permissible value, after how many days will it be safe to enter the room?
AIEEE 2007
83
Which of the following nuclear reactions will generate an isotope?
AIEEE 2007
84
Rate of a reaction can be expressed by Arrhenius equation as:
$$$k = A\,{e^{ - E/RT}}$$$ In this equation, E represents
AIEEE 2006
85
A reaction was found to be second order with respect to the concentration of carbon monoxide. If the concentration of carbon monoxide is doubled, with everything else kept the same, the rate of reaction will
AIEEE 2006
86
In the transformation of $${}_{92}^{238}U$$ to $${}_{92}^{234}U$$, if one emission is an α-particle, what should be the other emission(s)?
AIEEE 2006
87
The following mechanism has been proposed for the reaction of NO with Br2 to form NOBr:
NO(g) + Br2 (g) $$\leftrightharpoons$$ NOBr2 (g)
NOBr2 (g) + NO (g) $$\to$$ 2NOBr (g)
If the second step is the rate determining step, the order of the reaction with respect to NO(g) is
AIEEE 2006
88
The photon of hard gamma radiation knocks a proton out of $${}_{12}^{24}Mg$$ nucleus to form
AIEEE 2005
89
A schematic plot of $$ln$$ $${K_{eq}}$$ versus inverse of temperature for a reaction is shown below

AIEEE 2005 Chemistry - Chemical Kinetics and Nuclear Chemistry Question 158 English
The reaction must be
AIEEE 2005
90
t1/4 can be taken as the time taken for the concentration of a reactant to drop to $$3 \over 4$$ of its initial value. If the rate constant for a first order reaction is K, the t1/4 can be written as
AIEEE 2005
91
A reaction involving two different reactants can never be
AIEEE 2005
92
Hydrogen bomb is based on the principle of
AIEEE 2005
93
In a first order reaction, the concentration of the reactant decreases from 0.8 M to 0.4 M in 15 minutes. The time taken for the concentration to change from 0.1 M to 0.025 M is
AIEEE 2004
94
The rate equation for the reaction 2A + B $$\to$$ C is found to be: rate k[A][B]. The correct statement in relation to this reaction is that the
AIEEE 2004
95
Consider the following nuclear reactions
$${}_{92}^{238}M \to {}_Y^XN + 2{}_2^4He$$
$${}_Y^XN \to {}_B^AL + 2{\beta ^ + }$$
The number of neutrons in the element L is
AIEEE 2004
96
The half – life of a radioisotope is four hours. If the initial mass of the isotope was 200 g, the mass remaining after 24 hours undecayed is
AIEEE 2004
97
The half-life of a radioactive isotope is three hours. If the initial mass of the isotope were 256 g, the mass of it remaining undecayed after 18 hours would be
AIEEE 2003
98
In respect of the equation k = Ae-Ea/RT in chemical kinetics, which one of the following statements is correct?
AIEEE 2003
99
The rate law for a reaction between the substances A and B is given by Rate = k[A]n [B]m On doubling the concentration of A and halving the concentration of B, the ratio of the new rate to the earlier rate of the reaction will be as
AIEEE 2003
100
For the reaction system:

2NO(g) + O2(g) $$\to$$ 2NO2(g) volume is suddenly reduce to half its value by increasing the pressure on it. If the reaction is of first order with respect to O2 and second order with respect to NO, the rate of reaction will
AIEEE 2003
101
The radionucleide $${}_{90}^{234}Th$$ undergoes two successive $$\beta$$ -decays followed by one $$\alpha$$-decay. The atomic number and the mass number respectively of the resulting radionucleide are
AIEEE 2003
102
For the reaction A + 2B $$\to$$ C, rate is given by R = [A] [B]2 then the order of the reaction is
AIEEE 2002
103
Units of rate constant of first and zero order reactions in terms of molarity M unit are respectively
AIEEE 2002
104
The integrated rate equation is Rt = log C0 - log Ct . The straight line graph is obtained by plotting
AIEEE 2002
105
$$\beta$$ - particle is emitted in radioactivity by
AIEEE 2002
106
If half-life of a substance is 5 yrs, then the total amount of substance left after 15 years, when initial amount is 64 grams is
AIEEE 2002
107
The differential rate law for the reaction H2 + I2 $$\to$$ 2HI is
AIEEE 2002

Numerical

1

For the reaction $\mathrm{A} \rightarrow \mathrm{B}$ the following graph was obtained. The time required (in seconds) for the concentration of A to reduce to $2.5 \mathrm{~g} \mathrm{~L}^{-1}$ (if the initial concentration of A was $50 \mathrm{~g} \mathrm{~L}^{-1}$ ) is $\qquad$ . (Nearest integer)

Given : $\log 2=0.3010$

JEE Main 2025 (Online) 2nd April Evening Shift Chemistry - Chemical Kinetics and Nuclear Chemistry Question 10 English
JEE Main 2025 (Online) 2nd April Evening Shift
2

For the reaction A $\to$ products.

JEE Main 2025 (Online) 2nd April Morning Shift Chemistry - Chemical Kinetics and Nuclear Chemistry Question 12 English

The concentration of A at 10 minutes is _________ $\times 10^{-3} \mathrm{~mol} \mathrm{~L}^{-1}$ (nearest integer). The reaction was started with $2.5 \mathrm{~mol} \mathrm{~L}^{-1}$ of A .

JEE Main 2025 (Online) 2nd April Morning Shift
3

Consider a complex reaction taking place in three steps with rate constants $\mathrm{k}_1, \mathrm{k}_2$ and $\mathrm{k}_3$ respectively. The overall rate constant $k$ is given by the expression $k=\sqrt{\frac{k_1 k_3}{k_2}}$. If the activation energies of the three steps are 60, 30 and $10 \mathrm{~kJ} \mathrm{~mol}^{-1}$ respectively, then the overall energy of activation in $\mathrm{kJ} \mathrm{mol}^{-1}$ is _________ . (Nearest integer)

JEE Main 2025 (Online) 24th January Evening Shift
4

For the thermal decomposition of $\mathrm{N}_2 \mathrm{O}_5(\mathrm{~g})$ at constant volume, the following table can be formed, for the reaction mentioned below.

$$2 \mathrm{~N}_2 \mathrm{O}_5(\mathrm{~g}) \rightarrow 2 \mathrm{~N}_2 \mathrm{O}_4(\mathrm{~g})+\mathrm{O}_2(\mathrm{~g})$$

Sr. No. Time/s Total pressure/(atm)
1 0 0.6
2 100 '$\mathrm{x}$'

$\mathrm{x}=$ __________ $\times 10^{-3} \mathrm{~atm}$ [nearest integer]

Given : Rate constant for the reaction is $4.606 \times 10^{-2} \mathrm{~s}^{-1}$.

JEE Main 2025 (Online) 23rd January Morning Shift
5

$\mathrm{A \rightarrow B}$

The molecule A changes into its isomeric form B by following a first order kinetics at a temperature of 1000 K . If the energy barrier with respect to reactant energy for such isomeric transformation is $191.48 \mathrm{~kJ} \mathrm{~mol}^{-1}$ and the frequency factor is $10^{20}$, the time required for $50 \%$ molecules of A to become B is __________ picoseconds (nearest integer). $\left[\mathrm{R}=8.314 \mathrm{~J} \mathrm{~K}^{-1} \mathrm{~mol}^{-1}\right]$

JEE Main 2025 (Online) 22nd January Morning Shift
6

Consider the following first order gas phase reaction at constant temperature $$ \mathrm{A}(\mathrm{g}) \rightarrow 2 \mathrm{B}(\mathrm{~g})+\mathrm{C}(\mathrm{g})$$

If the total pressure of the gases is found to be 200 torr after 23 $$\mathrm{sec}$$. and 300 torr upon the complete decomposition of A after a very long time, then the rate constant of the given reaction is ________ $$\times 10^{-2} \mathrm{~s}^{-1}$$ (nearest integer)

[Given : $$\log _{10}(2)=0.301$$]

JEE Main 2024 (Online) 9th April Evening Shift
7

Given below are two statements :

Statement I : The rate law for the reaction $$A+B \rightarrow C$$ is rate $$(r)=k[A]^2[B]$$. When the concentration of both $$\mathrm{A}$$ and $$\mathrm{B}$$ is doubled, the reaction rate is increased "$$x$$" times.

Statement II : JEE Main 2024 (Online) 9th April Morning Shift Chemistry - Chemical Kinetics and Nuclear Chemistry Question 35 English

The figure is showing "the variation in concentration against time plot" for a "$$y$$" order reaction.

The Value of $$x+y$$ is __________.

JEE Main 2024 (Online) 9th April Morning Shift
8

Consider the following reaction

$$\mathrm{A}+\mathrm{B} \rightarrow \mathrm{C}$$

The time taken for A to become $$1 / 4^{\text {th }}$$ of its initial concentration is twice the time taken to become $$1 / 2$$ of the same. Also, when the change of concentration of B is plotted against time, the resulting graph gives a straight line with a negative slope and a positive intercept on the concentration axis.

The overall order of the reaction is ________.

JEE Main 2024 (Online) 8th April Morning Shift
9

Consider the two different first order reactions given below

$$\begin{aligned} & \mathrm{A}+\mathrm{B} \rightarrow \mathrm{C} \text { (Reaction 1) } \\ & \mathrm{P} \rightarrow \mathrm{Q} \text { (Reaction 2) } \end{aligned}$$

The ratio of the half life of Reaction 1 : Reaction 2 is $$5: 2$$ If $$t_1$$ and $$t_2$$ represent the time taken to complete $$2 / 3^{\text {rd }}$$ and $$4 / 5^{\text {th }}$$ of Reaction 1 and Reaction 2 , respectively, then the value of the ratio $$t_1: t_2$$ is _________ $$\times 10^{-1}$$ (nearest integer). [Given : $$\log _{10}(3)=0.477$$ and $$\log _{10}(5)=0.699$$]

JEE Main 2024 (Online) 6th April Evening Shift
10

Time required for $$99.9 \%$$ completion of a first order reaction is _________ times the time required for completion of $$90 \%$$ reaction.(nearest integer)

JEE Main 2024 (Online) 6th April Morning Shift
11

Consider the following single step reaction in gas phase at constant temperature.

$$2 \mathrm{~A}_{(\mathrm{g})}+\mathrm{B}_{(\mathrm{g})} \rightarrow \mathrm{C}_{(\mathrm{g})}$$

The initial rate of the reaction is recorded as $$\mathrm{r}_1$$ when the reaction starts with $$1.5 \mathrm{~atm}$$ pressure of $$\mathrm{A}$$ and $$0.7 \mathrm{~atm}$$ pressure of B. After some time, the rate $$r_2$$ is recorded when the pressure of C becomes $$0.5 \mathrm{~atm}$$. The ratio $$\mathrm{r}_1: \mathrm{r}_2$$ is _________ $$\times 10^{-1}$$. (Nearest integer)

JEE Main 2024 (Online) 5th April Evening Shift
12

During Kinetic study of reaction $$\mathrm{2 A+B \rightarrow C+D}$$, the following results were obtained :

$$\mathrm{A [M]}$$ $$\mathrm{B [M]}$$ initial rate of formation of $$\mathrm{D}$$
I 0.1 0.1 $$6.0\times10^{-3}$$
II 0.3 0.2 $$7.2\times10^{-2}$$
III 0.3 0.4 $$2.88\times10^{-1}$$
IV 0.4 0.1 $$2.40\times10^{-2}$$

Based on above data, overall order of the reaction is _________.

JEE Main 2024 (Online) 5th April Morning Shift
13

Consider the following reaction, the rate expression of which is given below

$$\begin{aligned} & \mathrm{A}+\mathrm{B} \rightarrow \mathrm{C} \\ & \text { rate }=\mathrm{k}[\mathrm{A}]^{1 / 2}[\mathrm{~B}]^{1 / 2} \end{aligned}$$

The reaction is initiated by taking $$1 \mathrm{~M}$$ concentration of $$\mathrm{A}$$ and $$\mathrm{B}$$ each. If the rate constant $$(\mathrm{k})$$ is $$4.6 \times 10^{-2} \mathrm{~s}^{-1}$$, then the time taken for $$\mathrm{A}$$ to become $$0.1 \mathrm{~M}$$ is _________ sec. (nearest integer)

JEE Main 2024 (Online) 4th April Evening Shift
14

Consider the following transformation involving first order elementary reaction in each step at constant temperature as shown below.

JEE Main 2024 (Online) 4th April Morning Shift Chemistry - Chemical Kinetics and Nuclear Chemistry Question 34 English

Some details of the above reactions are listed below.

Step Rate constant (sec$$^{-1}$$) Activation energy (kJ mol$$^{-1}$$)
1 $$\mathrm{k_1}$$ 300
2 $$\mathrm{k_2}$$ 200
3 $$\mathrm{k_3}$$ $$\mathrm{Ea_3}$$

If the overall rate constant of the above transformation (k) is given as $$\mathrm{k=\frac{k_1 k_2}{k_3}}$$ and the overall activation energy $$(\mathrm{E}_{\mathrm{a}})$$ is $$400 \mathrm{~kJ} \mathrm{~mol} \mathrm{~m}^{-1}$$, then the value of $$\mathrm{Ea}_3$$ is ________ integer)

JEE Main 2024 (Online) 4th April Morning Shift
15
The following data were obtained during the first order thermal decomposition of a gas A at constant volume :

$\mathrm{A}(\mathrm{g}) \rightarrow 2 \mathrm{~B}(\mathrm{~g})+\mathrm{C}(\mathrm{g})$

S.No. Time /s Total pressure /(atm)
1. 0 0.1
2. 115 0.28

The rate constant of the reaction is ________ $\times 10^{-2} \mathrm{~s}^{-1}$ (nearest integer)
JEE Main 2024 (Online) 1st February Evening Shift
16
The ratio of $\frac{{ }^{14} \mathrm{C}}{{ }^{12} \mathrm{C}}$ in a piece of wood is $\frac{1}{8}$ part that of atmosphere. If half life of ${ }^{14} \mathrm{C}$ is 5730 years, the age of wood sample is ________ years.
JEE Main 2024 (Online) 1st February Morning Shift
17

$$\mathrm{r}=\mathrm{k}[\mathrm{A}]$$ for a reaction, $$50 \%$$ of $$\mathrm{A}$$ is decomposed in 120 minutes. The time taken for $$90 \%$$ decomposition of $$\mathrm{A}$$ is _________ minutes.

JEE Main 2024 (Online) 31st January Evening Shift
18

$$\mathrm{NO}_2$$ required for a reaction is produced by decomposition of $$\mathrm{N}_2 \mathrm{O}_5$$ in $$\mathrm{CCl}_4$$ as by equation

$$2 \mathrm{~N}_2 \mathrm{O}_{5(\mathrm{~g})} \rightarrow 4 \mathrm{NO}_{2(\mathrm{~g})}+\mathrm{O}_{2(\mathrm{~g})}$$

The initial concentration of $$\mathrm{N}_2 \mathrm{O}_5$$ is $$3 \mathrm{~mol} \mathrm{~L}^{-1}$$ and it is $$2.75 \mathrm{~mol} \mathrm{~L}^{-1}$$ after 30 minutes.

The rate of formation of $$\mathrm{NO}_2$$ is $$\mathrm{x} \times 10^{-3} \mathrm{~mol} \mathrm{~L}^{-1} \mathrm{~min}^{-1}$$, value of $$\mathrm{x}$$ is _________. (nearest integer)

JEE Main 2024 (Online) 30th January Evening Shift
19

The rate of First order reaction is $$0.04 \mathrm{~mol} \mathrm{~L}^{-1} \mathrm{~s}^{-1}$$ at 10 minutes and $$0.03 \mathrm{~mol} \mathrm{~L}^{-1} \mathrm{~s}^{-1}$$ at 20 minutes after initiation. Half life of the reaction is _______ minutes.

(Given $$\log 2=0.3010, \log 3=0.4771$$)

JEE Main 2024 (Online) 30th January Morning Shift
20

The half-life of radioisotope bromine - 82 is 36 hours. The fraction which remains after one day is ________ $$\times 10^{-2}$$.

(Given antilog $$0.2006=1.587$$)

JEE Main 2024 (Online) 29th January Evening Shift
21

For a reaction taking place in three steps at same temperature, overall rate constant $$\mathrm{K}=\frac{\mathrm{K}_1 \mathrm{~K}_2}{\mathrm{~K}_3}$$. If $$\mathrm{Ea}_1, \mathrm{Ea}_2$$ and $$\mathrm{Ea}_3$$ are 40, 50 and $$60 \mathrm{~kJ} / \mathrm{mol}$$ respectively, the overall $$\mathrm{Ea}$$ is ________ $$\mathrm{kJ} / \mathrm{mol}$$.

JEE Main 2024 (Online) 29th January Morning Shift
22

Time required for completion of $$99.9 \%$$ of a First order reaction is ________ times of half life $$\left(t_{1 / 2}\right)$$ of the reaction.

JEE Main 2024 (Online) 27th January Evening Shift
23

Consider the following data for the given reaction

$$2 \mathrm{HI}_{(\mathrm{g})} \rightarrow \mathrm{H}_{2(\mathrm{~g})}+\mathrm{I}_{2(\mathrm{~g})}$$

JEE Main 2024 (Online) 27th January Morning Shift Chemistry - Chemical Kinetics and Nuclear Chemistry Question 44 English

The order of the reaction is _________.

JEE Main 2024 (Online) 27th January Morning Shift
24
For a reversible reaction $\mathrm{A} \rightleftharpoons \mathrm{B}$, the $\Delta \mathrm{H}_{\text{forward reaction}} = 20 \mathrm{~kJ} \mathrm{~mol}^{-1}$. The activation energy of the uncatalysed forward reaction is $300 \mathrm{~kJ} \mathrm{~mol}^{-1}$. When the reaction is catalysed keeping the reactant concentration same, the rate of the catalysed forward reaction at $27^{\circ} \mathrm{C}$ is found to be same as that of the uncatalysed reaction at $327^{\circ} \mathrm{C}$.

The activation energy of the catalysed backward reaction is ___________ $\mathrm{kJ}~ \mathrm{mol}^{-1}$.
JEE Main 2023 (Online) 15th April Morning Shift
25

A(g) $$\to$$ 2B(g) + C(g) is a first order reaction. The initial pressure of the system was found to be 800 mm Hg which increased to 1600 mm Hg after 10 min. The total pressure of the system after 30 min will be _________ mm Hg. (Nearest integer)

JEE Main 2023 (Online) 13th April Evening Shift
26

$$\mathrm{t}_{87.5}$$ is the time required for the reaction to undergo $$87.5 \%$$ completion and $$\mathrm{t}_{50}$$ is the time required for the reaction to undergo $$50 \%$$ completion. The relation between $$\mathrm{t}_{87.5}$$ and $$\mathrm{t}_{50}$$ for a first order reaction is $$\mathrm{t}_{87.5}=x \times \mathrm{t}_{50}$$ The value of $$x$$ is ___________. (Nearest integer)

JEE Main 2023 (Online) 13th April Morning Shift
27

The reaction $$2 \mathrm{NO}+\mathrm{Br}_{2} \rightarrow 2 \mathrm{NOBr}$$

takes places through the mechanism given below:

$$\mathrm{NO}+\mathrm{Br}_{2} \Leftrightarrow \mathrm{NOBr}_{2}$$ (fast)

$$\mathrm{NOBr}_{2}+\mathrm{NO} \rightarrow 2 \mathrm{NOBr}$$ (slow)

The overall order of the reaction is ___________.

JEE Main 2023 (Online) 12th April Morning Shift
28

$$\mathrm{KClO}_{3}+6 \mathrm{FeSO}_{4}+3 \mathrm{H}_{2} \mathrm{SO}_{4} \rightarrow \mathrm{KCl}+3 \mathrm{Fe}_{2}\left(\mathrm{SO}_{4}\right)_{3}+3 \mathrm{H}_{2} \mathrm{O}$$

The above reaction was studied at $$300 \mathrm{~K}$$ by monitoring the concentration of $$\mathrm{FeSO}_{4}$$ in which initial concentration was $$10 \mathrm{M}$$ and after half an hour became 8.8 M. The rate of production of $$\mathrm{Fe}_{2}\left(\mathrm{SO}_{4}\right)_{3}$$ is _________ $$\times 10^{-6} \mathrm{~mol} \mathrm{~L} \mathrm{~s}^{-1}$$ (Nearest integer)

JEE Main 2023 (Online) 11th April Morning Shift
29

The number of incorrect statement/s from the following is ___________

A. The successive half lives of zero order reactions decreases with time.

B. A substance appearing as reactant in the chemical equation may not affect the rate of reaction

C. Order and molecularity of a chemical reaction can be a fractional number

D. The rate constant units of zero and second order reaction are $$\mathrm{mol} ~\mathrm{L}^{-1} \mathrm{~s}^{-1}$$ and $$\mathrm{mol}^{-1} \mathrm{~L} \mathrm{~s}^{-1}$$ respectively

JEE Main 2023 (Online) 10th April Evening Shift
30

A molecule undergoes two independent first order reactions whose respective half lives are 12 min and 3 min. If both the reactions are occurring then the time taken for the 50% consumption of the reactant is ___________ min. (Nearest integer)

JEE Main 2023 (Online) 10th April Morning Shift
31

The number of given statement/s which is/are correct is __________.

(A) The stronger the temperature dependence of the rate constant, the higher is the activation energy.

(B) If a reaction has zero activation energy, its rate is independent of temperature.

(C) The stronger the temperature dependence of the rate constant, the smaller is the activation energy.

(D) If there is no correlation between the temperature and the rate constant then it means that the reaction has negative activation energy.

JEE Main 2023 (Online) 8th April Morning Shift
32

$$\mathrm{A}$$ $$\rightarrow \mathrm{B}$$

The above reaction is of zero order. Half life of this reaction is $$50 \mathrm{~min}$$. The time taken for the concentration of $$\mathrm{A}$$ to reduce to one-fourth of its initial value is ____________ min. (Nearest integer)

JEE Main 2023 (Online) 1st February Evening Shift
33

A and B are two substances undergoing radioactive decay in a container. The half life of A is 15 min and that of B is 5 min. If the initial concentration of B is 4 times that of A and they both start decaying at the same time, how much time will it take for the concentration of both of them to be same? _____________ min.

JEE Main 2023 (Online) 1st February Morning Shift
34
The rate constant for a first order reaction is $20 \mathrm{~min}^{-1}$. The time required for the initial concentration of the reactant to reduce to its $\frac{1}{32}$ level is _______ $\times 10^{-2} \mathrm{~min}$. (Nearest integer)

(Given : $\ln 10=2.303$ and $$ \log 2=0.3010 \text { )}$$
JEE Main 2023 (Online) 31st January Evening Shift
35

A $$\to$$ B

The rate constants of the above reaction at 200 K and 300 K are 0.03 min$$^{-1}$$ and 0.05 min$$^{-1}$$ respectively. The activation energy for the reaction is ___________ J (Nearest integer)

(Given : $$\mathrm{ln10=2.3}$$

$$\mathrm{R=8.3~J~K^{-1}~mol^{-1}}$$

$$\mathrm{\log5=0.70}$$

$$\mathrm{\log3=0.48}$$

$$\mathrm{\log2=0.30}$$)

JEE Main 2023 (Online) 31st January Morning Shift
36
An organic compound undergoes first-order decomposition. If the time taken for the $60 \%$ decomposition is $540 \mathrm{~s}$, then the time required for $90 \%$ decomposition will be ________ s. (Nearest integer).

Given: $\ln 10=2.3 ; \log 2=0.3$
JEE Main 2023 (Online) 30th January Evening Shift
37

If compound A reacts with B following first order kinetics with rate constant $$2.011 \times 10^{-3} \mathrm{~s}^{-1}$$. The time taken by $$\mathrm{A}$$ (in seconds) to reduce from $$7 \mathrm{~g}$$ to $$2 \mathrm{~g}$$ will be ___________. (Nearest Integer)

$$[\log 5=0.698, \log 7=0.845, \log 2=0.301]$$

JEE Main 2023 (Online) 30th January Morning Shift
38

For conversion of compound A $$\to$$ B, the rate constant of the reaction was found to be $$\mathrm{4.6\times10^{-5}~L~mol^{-1}~s^{-1}}$$. The order of the reaction is ____________.

JEE Main 2023 (Online) 29th January Evening Shift
39

For certain chemical reaction $$X\to Y$$, the rate of formation of product is plotted against the time as shown in the figure. The number of $$\mathrm{\underline {correct} }$$ statement/s from the following is ___________.

JEE Main 2023 (Online) 29th January Morning Shift Chemistry - Chemical Kinetics and Nuclear Chemistry Question 62 English

(A) Over all order of this reaction is one.

(B) Order of this reaction can't be determined.

(C) In region I and III, the reaction is of first and zero order respectively.

(D) In region-II, the reaction is of first order.

(E) In region-II, the order of reaction is in the range of 0.1 to 0.9.

JEE Main 2023 (Online) 29th January Morning Shift
40

A first order reaction has the rate constant, $$\mathrm{k=4.6\times10^{-3}~s^{-1}}$$. The number of correct statement/s from the following is/are __________

Given : $$\mathrm{\log3=0.48}$$

A. Reaction completes in 1000 s.

B. The reaction has a half-life of 500 s.

C. The time required for 10% completion is 25 times the time required for 90% completion.

D. The degree of dissociation is equal to ($$\mathrm{1-e^{-kt}}$$)

E. The rate and the rate constant have the same unit.

JEE Main 2023 (Online) 25th January Evening Shift
41

For the first order reaction A $$\to$$ B, the half life is 30 min. The time taken for 75% completion of the reaction is _________ min. (Nearest integer)

Given : log 2 = 0.3010

log 3 = 0.4771

log 5 = 0.6989

JEE Main 2023 (Online) 25th January Morning Shift
42

The number of correct statement/s from the following is __________

A. Larger the activation energy, smaller is the value of the rate constant.

B. The higher is the activation energy, higher is the value of the temperature coefficient.

C. At lower temperatures, increase in temperature causes more change in the value of k than at higher temperature

D. A plot of $$\mathrm{\ln k}$$ vs $$\frac{1}{T}$$ is a straight line with slope equal to $$-\frac{E_a}{R}$$

JEE Main 2023 (Online) 24th January Morning Shift
43

Assuming $$1 \,\mu \mathrm{g}$$ of trace radioactive element X with a half life of 30 years is absorbed by a growing tree. The amount of X remaining in the tree after 100 years is ______ $$\times\, 10^{-1} \mu \mathrm{g}$$.

[Given : ln 10 = 2.303; log 2 = 0.30]

JEE Main 2022 (Online) 29th July Evening Shift
44

The reaction between X and Y is first order with respect to X and zero order with respect to Y.

Experiment $${{[X]} \over {mol\,{L^{ - 1}}}}$$ $${{[Y]} \over {mol\,{L^{ - 1}}}}$$ $${{Initial\,rate} \over {mol\,{L^{ - 1}}\,{{\min }^{ - 1}}}}$$
I 0.1 0.1 $$2 \times {10^{ - 3}}$$
I L 0.2 $$4 \times {10^{ - 3}}$$
III 0.4 0.4 $$M \times {10^{ - 3}}$$
IV 0.1 0.2 $$2 \times {10^{ - 3}}$$

Examine the data of table and calculate ratio of numerical values of M and L. (Nearest Integer)

JEE Main 2022 (Online) 29th July Morning Shift
45

For a reaction, given below is the graph of $$\ln k$$ vs $${1 \over T}$$. The activation energy for the reaction is equal to ____________ $$\mathrm{cal} \,\mathrm{mol}^{-1}$$. (nearest integer)

(Given : $$\mathrm{R}=2 \,\mathrm{cal} \,\mathrm{K}^{-1} \,\mathrm{~mol}^{-1}$$ )

JEE Main 2022 (Online) 28th July Evening Shift Chemistry - Chemical Kinetics and Nuclear Chemistry Question 72 English

JEE Main 2022 (Online) 28th July Evening Shift
46

For the given first order reaction

$$\mathrm{A} \rightarrow \mathrm{B}$$

the half life of the reaction is $$0.3010 \mathrm{~min}$$. The ratio of the initial concentration of reactant to the concentration of reactant at time $$2.0 \mathrm{~min}$$ will be equal to ___________. (Nearest integer)

JEE Main 2022 (Online) 28th July Morning Shift
47

$$\matrix{ {[A]} & \to & {[B]} \cr {{\mathop{\rm Reactant}\nolimits} } & {} & {{\mathop{\rm Product}\nolimits} } \cr } $$

If formation of compound $$[\mathrm{B}]$$ follows the first order of kinetics and after 70 minutes the concentration of $$[\mathrm{A}]$$ was found to be half of its initial concentration. Then the rate constant of the reaction is $$x \times 10^{-6} \mathrm{~s}^{-1}$$. The value of $$x$$ is ______________. (Nearest Integer)

JEE Main 2022 (Online) 27th July Evening Shift
48

$$2 \mathrm{NO}+2 \mathrm{H}_{2} \rightarrow \mathrm{N}_{2}+2 \mathrm{H}_{2} \mathrm{O}$$

The above reaction has been studied at $$800^{\circ} \mathrm{C}$$. The related data are given in the table below

Reaction serial number Initial Pressure of $${H_2}/kPa$$ Initial Pressure of $$NO/kPa$$ Initial rate $$\left( {{{ - dp} \over {dt}}} \right)/(kPa/s)$$
1 65.6 40.0 0.135
2 65.6 20.1 0.033
3 38.6 65.6 0.214
4 19.2 65.6 0.106

The order of the reaction with respect to NO is ___________.

JEE Main 2022 (Online) 27th July Morning Shift
49

For a reaction $$\mathrm{A} \rightarrow 2 \mathrm{~B}+\mathrm{C}$$ the half lives are $$100 \mathrm{~s}$$ and $$50 \mathrm{~s}$$ when the concentration of reactant $$\mathrm{A}$$ is $$0.5$$ and $$1.0 \mathrm{~mol} \mathrm{~L}^{-1}$$ respectively. The order of the reaction is ______________ . (Nearest Integer)

JEE Main 2022 (Online) 26th July Morning Shift
50

For the decomposition of azomethane.

CH3N2CH3(g) $$\to$$ CH3CH3(g) + N2(g), a first order reaction, the variation in partial pressure with time at 600 K is given as

JEE Main 2022 (Online) 25th July Evening Shift Chemistry - Chemical Kinetics and Nuclear Chemistry Question 79 English

The half life of the reaction is __________ $$\times$$ 10$$-$$5 s. [Nearest integer]

JEE Main 2022 (Online) 25th July Evening Shift
51

The half life for the decomposition of gaseous compound $$\mathrm{A}$$ is $$240 \mathrm{~s}$$ when the gaseous pressure was 500 Torr initially. When the pressure was 250 Torr, the half life was found to be $$4.0$$ min. The order of the reaction is ______________. (Nearest integer)

JEE Main 2022 (Online) 25th July Morning Shift
52

For the reaction P $$\to$$ B, the values of frequency factor A and activation energy EA are 4 $$\times$$ 1013 s$$-$$1 and 8.3 kJ mol$$-$$1 respectively. If the reaction is of first order, the temperature at which the rate constant is 2 $$\times$$ 10$$-$$6 s$$-$$1 is _____________ $$\times$$ 10$$-$$1 K.

(Given : ln 10 = 2.3, R = 8.3 J K$$-$$1 mol$$-$$1, log2 = 0.30)

JEE Main 2022 (Online) 30th June Morning Shift
53

The equation

k = (6.5 $$\times$$ 1012s$$-$$1)e$$-$$26000K/T

is followed for the decomposition of compound A. The activation energy for the reaction is ________ kJ mol$$-$$1. [nearest integer]

(Given : R = 8.314 J K$$-$$1 mol$$-$$1)

JEE Main 2022 (Online) 29th June Evening Shift
54

The activation energy of one of the reactions in a biochemical process is 532611 J mol$$-$$1. When the temperature falls from 310 K to 300 K, the change in rate constant observed is k300 = x $$\times$$ 10$$-$$3 k310. The value of x is ____________.

[Given : $$\ln 10 = 2.3$$, R = 8.3 J K$$-$$1 mol$$-$$1]

JEE Main 2022 (Online) 29th June Morning Shift
55

A radioactive element has a half life of 200 days. The percentage of original activity remaining after 83 days is ___________. (Nearest integer)

(Given : antilog 0.125 = 1.333, antilog 0.693 = 4.93)

JEE Main 2022 (Online) 28th June Evening Shift
56

For a first order reaction A $$\to$$ B, the rate constant, k = 5.5 $$\times$$ 10$$-$$14 s$$-$$1. The time required for 67% completion of reaction is x $$\times$$ 10$$-$$1 times the half life of reaction. The value of x is _____________ (Nearest integer)

(Given : log 3 = 0.4771)

JEE Main 2022 (Online) 28th June Morning Shift
57

It has been found that for a chemical reaction with rise in temperature by 9 K the rate constant gets doubled. Assuming a reaction to be occurring at 300 K, the value of activation energy is found to be ____________ kJ mol$$-$$1. [nearest integer]

(Given ln10 = 2.3, R = 8.3 J K$$-$$1 mol$$-$$1, log 2 = 0.30)

JEE Main 2022 (Online) 27th June Evening Shift
58

The rate constant for a first order reaction is given by the following equation:

$$\ln k = 33.24 - {{2.0 \times {{10}^4}\,K} \over T}$$

The activation energy for the reaction is given by ____________ kJ mol$$-$$1. (In nearest integer) (Given : R = 8.3 J K$$-$$1 mol$$-$$1)

JEE Main 2022 (Online) 27th June Morning Shift
59

Catalyst A reduces the activation energy for a reaction by 10 kJ mol$$-$$1 at 300 K. The ratio of rate constants, $${{{}^kT,\,Catalysed} \over {{}^kT,\,Uncatalysed}}$$ is ex. The value of x is ___________. [nearest integer]

[Assume that the pre-exponential factor is same in both the cases. Given R = 8.31 J K$$-$$1 mol$$-$$1]

JEE Main 2022 (Online) 26th June Evening Shift
60

A flask is filled with equal moles of A and B. The half lives of A and B are 100 s and 50 s respectively and are independent of the initial concentration. The time required for the concentration of A to be four times that of B is ___________ s.

(Given : ln 2 = 0.693)

JEE Main 2022 (Online) 26th June Morning Shift
61

At 345 K, the half life for the decomposition of a sample of a gaseous compound initially at 55.5 kPa was 340 s. When the pressure was 27.8 kPa, the half life was found to be 170 s. The order of the reaction is ____________. [integer answer]

JEE Main 2022 (Online) 25th June Evening Shift
62

For a given chemical reaction

$$\gamma$$1A + $$\gamma$$2B $$\to$$ $$\gamma$$3C + $$\gamma$$4D

Concentration of C changes from 10 mmol dm$$-$$3 to 20 mmol dm$$-$$3 in 10 seconds. Rate of appearance of D is 1.5 times the rate of disappearance of B which is twice the rate of disappearance A. The rate of appearance of D has been experimentally determined to be 9 mmol dm$$-$$3 s$$-$$1. Therefore, the rate of reaction is _____________ mmol dm$$-$$3 s$$-$$1. (Nearest Integer)

JEE Main 2022 (Online) 25th June Morning Shift
63

The rate constants for decomposition of acetaldehyde have been measured over the temperature range 700 - 1000 K. The data has been analysed by plotting ln k vs $${{{{10}^3}} \over T}$$ graph. The value of activation energy for the reaction is ___________ kJ mol$$-$$1. (Nearest integer)

(Given : R = 8.31 J K$$-$$1 mol$$-$$1)

JEE Main 2022 (Online) 24th June Morning Shift Chemistry - Chemical Kinetics and Nuclear Chemistry Question 82 English

JEE Main 2022 (Online) 24th June Morning Shift
64
For the reaction A $$\to$$ B, the rate constant k(in s$$-$$1) is given by

$${\log _{10}}k = 20.35 - {{(2.47 \times {{10}^3})} \over T}$$

The energy of activation in kJ mol$$-$$1 is ____________. (Nearest integer) [Given : R = 8.314 J K$$-$$1 mol$$-$$1]
JEE Main 2021 (Online) 31st August Evening Shift
65
For a first order reaction, the ratio of the time for 75% completion of a reaction to the time for 50% completion is ____________. (Integer answer)
JEE Main 2021 (Online) 31st August Morning Shift
66
According to the following figure, the magnitude of the enthalpy change of the reaction

A + B $$\to$$ M + N in kJ mol$$-$$ is equal to ___________. (Integer answer)

JEE Main 2021 (Online) 31st August Morning Shift Chemistry - Chemical Kinetics and Nuclear Chemistry Question 97 English
JEE Main 2021 (Online) 31st August Morning Shift
67
The first order rate constant for the decomposition of CaCO3 at 700 K is 6.36 $$\times$$ 10$$-$$3s$$-$$1 and activation energy is 209 kJ mol$$-$$1. Its rate constant (in s$$-$$1) at 600 K is x $$\times$$ 10$$-$$6. The value of x is ___________. (Nearest integer)

[Given R = 8.31 J K$$-$$ mol$$-$$1; log 6.36 $$\times$$ 10$$-$$3 = $$-$$2.19, 10$$-$$4.79 = 1.62 $$\times$$ 10$$-$$5]
JEE Main 2021 (Online) 27th August Evening Shift
68
The reaction that occurs in a breath analyser, a device used to determine the alcohol level in a person's blood stream is

$$2{K_2}C{r_2}{O_7} + 8{H_2}S{O_4} + 3{C_2}{H_6}O \to 2C{r_2}{(S{O_4})_3} + 3{C_2}{H_4}{O_2} + 2{K_2}S{O_4} + 11{H_2}O$$

If the rate of appearance of Cr2(SO4)3 is 2.67 mol min$$-$$1 at a particular time, the rate of disappearance of C2H6O at the same time is _____________ mol min$$-$$1. (Nearest integer)
JEE Main 2021 (Online) 27th August Morning Shift
69
The following data was obtained for chemical reaction given below at 975 K.

2NO(g) + 2H2(g) $$\to$$ N2(g) + 2H2O(g)

JEE Main 2021 (Online) 26th August Morning Shift Chemistry - Chemical Kinetics and Nuclear Chemistry Question 100 English

The order of the reaction with respect to NO is ___________. [Integer answer]
JEE Main 2021 (Online) 26th August Morning Shift
70
For the first order reaction A $$\to$$ 2B, 1 mole of reactant A gives 0.2 moles of B after 100 minutes. The half life of the reaction is __________ min. (Round off to the nearest integer).

[Use : ln 2 = 0.69, ln 10 = 2.3]

Properties of logarithms : ln xy = y ln x;

$$\ln \left( {{x \over y}} \right) = \ln x - \ln y$$

(Round off to the nearest integer)
JEE Main 2021 (Online) 27th July Evening Shift
71
For a chemical reaction A $$\to$$ B, it was found that concentration of B is increased by 0.2 mol L$$-$$ in 30 min. The average rate of the reaction is ____________ $$\times$$ 10$$-$$1 mol L$$-$$1 h$$-$$1. (in nearest integer)
JEE Main 2021 (Online) 25th July Evening Shift
72
$${N_2}{O_{5(g)}} \to 2N{O_{2(g)}} + {1 \over 2}{O_{2(g)}}$$

In the above first order reaction the initial concentration of N2O5 is 2.40 $$\times$$ 10$$-$$2 mol L$$-$$1 at 318 K. The concentration of N2O5 after 1 hour was 1.60 $$\times$$ 10$$-$$2 mol L$$-$$1. The rate constant of the reaction at 318 K is ______________ $$\times$$ 10$$-$$3 min$$-$$1. (Nearest integer)

[Given : log 3 = 0.477, log 5 = 0.699]
JEE Main 2021 (Online) 22th July Evening Shift
73
$$PC{l_5}(g) \to PC{l_3}(g) + C{l_2}(g)$$

In the above first order reaction the concentration of PCl5 reduces from initial concentration 50 mol L$$-$$1 to 10 mol L$$-$$1 in 120 minutes at 300 K. The rate constant for the reaction at 300 K is x $$\times$$ 10$$-$$2 min$$-$$1. The value of x is __________. [Given log5 = 0.6989]
JEE Main 2021 (Online) 20th July Evening Shift
74
The inactivation rate of a viral preparation is proportional to the amount of virus. In the first minute after preparation, 10% of the virus is inactivated. The rate constant for viral inactivation is ___________ $$\times$$ 10$$-$$3 min$$-$$1. (Nearest integer)

[Use : ln 10 = 2.303; log10 3 = 0.477; property
of logarithm : log xy = y log x]
JEE Main 2021 (Online) 20th July Morning Shift
75
A reaction has a half life of 1 min. The time required for 99.9% completion of the reaction is _________ min. (Round off to the Nearest Integer). [Use : ln 2 = 0.69; ln 10 = 2.3]
JEE Main 2021 (Online) 18th March Evening Shift
76
2NO(g) + Cl2(g) $$\rightleftharpoons $$ 2NOCl(s)

This reaction was studied at $$-$$10$$^\circ$$ and the following data was obtained

Run $${[NO]_0}$$ $${[C{l_2}]_0}$$ $${r_0}$$
1 0.10 0.10 0.18
2 0.10 0.20 0.35
3 0.20 0.20 1.40


$${[NO]_0}$$ and $${[C{l_2}]_0}$$ are the initial concentrations and r0 is the initial reaction rate.

The overall order of the reaction is __________. (Round off to the Nearest Integer).
JEE Main 2021 (Online) 18th March Morning Shift
77
The reaction 2A + B2 $$ \to $$ 2AB is an elementary reaction.

For a certain quantity of reactants, if the volume of the reaction vessel is reduced by a factor of 3, the rate of the reaction increases by a factor of ____________. (Round off to the Nearest Integer).
JEE Main 2021 (Online) 17th March Evening Shift
78
For a certain first order reaction 32% of the reactant is left after 570s. The rate constant of this reaction is _________ $$\times$$ 10$$-$$3 s$$-$$1. (Round off to the Nearest Integer). [Given : log102 = 0.301, ln10 = 2.303]
JEE Main 2021 (Online) 17th March Morning Shift
79
A and B decompose via first order kinetics with half-lives 54.0 min and 18.0 min respectively. Starting from an equimolar non reactive mixture of A and B, the time taken for the concentration of A to become 16 times that of B is _________ min. (Round off to the Nearest Integer).
JEE Main 2021 (Online) 16th March Evening Shift
80
The decomposition of formic acid on gold surface follows first order kinetics. If the rate constant at 300 K is 1.0 $$\times$$ 10$$-$$3 s$$-$$1 and the activation energy Ea = 11.488 kJ mol$$-$$1, the rate constant at 200 K is ____________ $$\times$$ 10$$-$$5 s$$-$$1. (Round off to the Nearest Integer). (Given : R = 8.314 J mol$$-$$1 K$$-$$1)
JEE Main 2021 (Online) 16th March Morning Shift
81
If the activation energy of a reaction is 80.9 kJ mol$$-$$1, the fraction of molecules at 700 K, having enough energy to react to form
products is e$$-$$x. The value of x is __________. (Rounded off to the nearest integer) [Use R = 8.31 J K$$-$$1 mol$$-$$1]
JEE Main 2021 (Online) 26th February Evening Shift
82
The rate constant of a reaction increases by five times on increase in temperature from 27$$^\circ$$C to 52$$^\circ$$C. The value of activation energy in kJ mol$$-$$1 is _________. (Rounded off to the nearest integer)

[R = 8.314 J K$$-$$1mol$$-$$1]
JEE Main 2021 (Online) 25th February Evening Shift
83
For the reaction, aA + bB $$ \to $$ cC + dD, the plot of log k vs $${1 \over T}$$ is given below :

JEE Main 2021 (Online) 25th February Morning Shift Chemistry - Chemical Kinetics and Nuclear Chemistry Question 117 English
The temperature at which the rate constant of the reaction is 10-4 s-1 is _________ K. (Rounded off to the nearest integer)

[Given : The rate constant of the reaction is 10-5 s-1 at 500 K.]
JEE Main 2021 (Online) 25th February Morning Shift
84
Sucrose hydrolyses in acid solution into glucose and fructose following first order rate law with a half-life of 3.33 h at 25$$^\circ$$C. After 9 h, the fraction of sucrose remaining is f. The value of $${\log _{10}}\left( {{1 \over f}} \right)$$ is ________ $$\times$$ 10$$-$$2. (Rounded off to the nearest integer)

[Assume : ln 10 = 2.303, ln 2 = 0.693]
JEE Main 2021 (Online) 24th February Evening Shift
85
Gaseous cyclobutene isomerises to butadiene in a first order process which has a 'k' value of 3.3 $$ \times $$ 10-4 s-1 at 153°C. The time in minutes it takes for the isomerization to proceed 40% to completion at this temperature is ______.
(Rounded off to the nearest integer)
JEE Main 2021 (Online) 24th February Morning Shift
86
The rate of a reaction decreased by 3.555 times when the temperature was changed from 40oC to 30oC. The activation energy (in kJ mol–1) of the reaction is _______.

Take; R = 8.314 J mol–1 K–1 ln 3.555 = 1.268
JEE Main 2020 (Online) 6th September Evening Slot
87
The number of molecules with energy greater than the threshold energy for a reaction increases five fold by a rise of temperature from 27oC to 42oC. Its energy of activation in J/mol is _____.
(Take ln 5 = 1.6094; R = 8.314 J mol–1 K–1)
JEE Main 2020 (Online) 4th September Evening Slot
88
If 75% of a first order reaction was completed in 90 minutes, 60% of the same reaction would be completed in approximately (in minutes) _______.

(Take : log 2 = 0.30; log 2.5 = 0.40)
JEE Main 2020 (Online) 4th September Morning Slot
89
A sample of milk splits after 60 min. at 300 K and after 40 min. at 400 K when the population of lactobacillus acidophilus in it doubles. The activa tion energy (in kJ/ mol) for this process is closest to__________.

(Given, R = 8.3 J mol–1 K–1, $$\ln \left( {{3 \over 2}} \right) = 0.4$$, e–3 = 4.0)
JEE Main 2020 (Online) 9th January Evening Slot
90
During the nuclear explosion, one of the products is 90Sr with half life of 6.93 years. If 1 $$\mu $$ g of 90Sr was absorbed in the bones of newly born baby in placed of Ca, how much time, in years, is required to reduce much time, in year, is required to reduce it by 90% if it not lost metabolically.
JEE Main 2020 (Online) 7th January Morning Slot
EXAM MAP
Medical
NEETAIIMS
Graduate Aptitude Test in Engineering
GATE CSEGATE ECEGATE EEGATE MEGATE CEGATE PIGATE IN
Civil Services
UPSC Civil Service
Defence
NDA
Staff Selection Commission
SSC CGL Tier I
CBSE
Class 12