Question 1: Palette 1/72

NEET 2026 MCQ

$ \text { Match List I with List II : } $

List-I (Order of reaction)		List-II (Unit of rate constant)
A.	Zero order	I.	$\mathrm{mol}^{-1} \mathrm{~L} \mathrm{~s}^{-1}$
B.	First order	II.	$\mathrm{mol}^{-2} \mathrm{~L}^2 \mathrm{~s}^{-1}$
C.	Second order	III.	$\mathrm{s}^{-1}$
D.	Third order	IV.	$\mathrm{mol} \mathrm{L}^{-1} \mathrm{~s}^{-1}$

Choose the correct answer from the options given below :

A

A-IV, B-II, C-I, D-III

B

A-IV, B-III, C-I, D-II

C

A-IV, B-III, C-II, D-I

D

A-I, B-II, C-III, D-IV

Question 2: Palette 2/72

NEET 2026 MCQ

For a certain reaction $R \rightarrow$ Product, the plot of concentration $[R]$ vs time has a negative slope as shown. The order of reaction is :

A

0

B

1

C

2

D

2.5

Question 3: Palette 3/72

NEET 2026 MCQ

Given below is an expression for the rate constant of a first-order reaction occurring at a certain temperature, $\mathrm{T}(\mathrm{K})$.

$ \operatorname{lnk}=14.34-\frac{1.25 \times 10^4}{T} $

The energy of activation in $\mathrm{kcal} \mathrm{mol}^{-1}$ for the reaction is :

(Given: $\mathrm{k}^{-1} \mathrm{~s} \mathrm{~s}^{-1}, \mathrm{R}=1.987 \mathrm{cal} \mathrm{mol}^{-1} \mathrm{~K}^{-1}$ )

A

24.84

B

14.34

C

18.63

D

12.42

Question 4: Palette 4/72

NEET 2026 MCQ

For an elementary chemical reaction, the Arrhenius plot is given below.

If the energy of activation is $6.64 \mathrm{~kJ} \mathrm{~mol}^{-1}$ and $\mathrm{R}=8.3 \mathrm{~J} \mathrm{~K}^{-1} \mathrm{~mol}^{-1}$, the temperature at which the rate constant becomes $\mathrm{e}^2 \mathrm{~min}^{-1}$, is

A

250 K

B

125 K

C

150 K

D

200 K

Question 5: Palette 5/72

NEET 2026 MCQ

$2 A \xrightarrow{k} B$ is a zero-order reaction, where $k=1.0 \mathrm{~mol} \mathrm{~L}^{-1} \mathrm{~min}^{-1}$. If the initial concentration of $A$ is 2 M , then the time taken to complete $75 \%$ of the reaction will be

A

2.0 min

B

1.5 min

C

0.75 min

D

1.0 min

Question 6: Palette 6/72

NEET 2025 MCQ

If the rate constant of a reaction is $0.03 \mathrm{~s}^{-1}$, how much time does it take for $7.2 \mathrm{~mol} \mathrm{~L}^{-1}$ concentration of the reactant to get reduced to $0.9 \mathrm{~mol} \mathrm{~L}^{-1}$ ? (Given: $\log 2=0.301$ )

A

210 s

B

21.0 s

C

69.3 s

D

23.1 s

Question 7: Palette 7/72

NEET 2025 MCQ

If the half-life ( $t_{1 / 2}$ ) for a first order reaction is 1 minute, then the time required for $99.9 \%$ completion of the reaction is closest to :

A

5 minutes

B

10 minutes

C

2 minutes

D

4 minutes

Question 8: Palette 8/72

NEET 2024 MCQ

Following data is for a reaction between reactants A and B :

Rate $\mathrm{mol} \mathrm{~L}^{-1} \mathrm{~s}^{-1}$	$\mathrm{[A]}$	$\mathrm{[B]}$
$ 2 \times 10^{-3} $	0.1 M	0.1 M
$ 4 \times 10^{-3} $	0.2 M	0.1 M
$ 1.6 \times 10^{-2} $	0.2 M	0.2 M

$ \text { The order of the reaction with respect to } \mathrm{A} \text { and } \mathrm{B} \text {, respectively, are } $

A

1, 0

B

0, 1

C

1, 2

D

2, 1

Question 9: Palette 9/72

NEET 2024 MCQ

Which of the following plot represents the variation of $\ln \mathrm{k}$ versus $\frac{1}{\mathrm{~T}}$ in accordance with Arrhenius equation?

A

B

C

D

Question 10: Palette 10/72

NEET 2024 MCQ

Rate constants of a reaction at $500 \mathrm{~K}$ and $700 \mathrm{~K}$ are $0.04 \mathrm{~s}^{-1}$ and $0.14 \mathrm{~s}^{-1}$, respectively; then, activation energy of the reaction is :

(Given: $\log 3.5=0.5441, \mathrm{R}=8.31 \mathrm{~J} \mathrm{~K}^{-1} \mathrm{~mol}^{-1}$)

A

182310 J

B

18500 J

C

18219 J

D

18030 J

Question 11: Palette 11/72

NEET 2024 MCQ

Activation energy of any chemical reaction can be calculated if one knows the value of

A

rate constant at standard temperature

B

probability of collision

C

orientation of reactant molecules during collision

D

rate constant at two different temperatures

Question 12: Palette 12/72

NEET 2024 MCQ

Which plot of $\ln \mathrm{k}$ vs $\frac{1}{\mathrm{~T}}$ is consistent with Arrhenius equation?

A

B

C

D

Question 13: Palette 13/72

NEET 2024 MCQ

The rate of a reaction quadruples when temperature changes from $27^{\circ} \mathrm{C}$ to $57^{\circ} \mathrm{C}$. Calculate the energy of activation.

Given $\mathrm{R}=8.314 \mathrm{~J} \mathrm{~K}^{-1} \mathrm{~mol}^{-1}, \log 4=0.6021$

A

$38.04 \mathrm{~kJ} / \mathrm{mol}$

B

$380.4 \mathrm{~kJ} / \mathrm{mol}$

C

$3.80 \mathrm{~kJ} / \mathrm{mol}$

D

$3804 \mathrm{~kJ} / \mathrm{mol}$

Question 14: Palette 14/72

NEET 2023 MCQ

For a reaction $3 \mathrm{~A} \rightarrow 2 \mathrm{~B}$

The average rate of appearance of $\mathrm{B}$ is given by $\frac{\Delta[B]}{\Delta t}$. The correct relation between the average rate of appearance of $\mathrm{B}$ with the average rate of disappearance of A is given in option :

A

$\frac{-\Delta[\mathrm{A}]}{\Delta \mathrm{t}}$

B

$\frac{-3 \Delta[\mathrm{A}]}{2 \Delta t}$

C

$\frac{-2 \Delta[\mathrm{A}]}{3 \Delta \mathrm{t}}$

D

$\frac{\Delta[\mathrm{A}]}{\Delta t}$

Question 15: Palette 15/72

NEET 2023 MCQ

The correct options for the rate law that corresponds to overall first order reaction is

A

Rate $=\mathrm{k}[\mathrm{A}]^0[\mathrm{~B}]^2$

B

Rate $=\mathrm{k}[\mathrm{A}][\mathrm{B}]$

C

Rate $=\mathrm{k}[\mathrm{A}]^{1 / 2}[\mathrm{~B}]^2$

D

Rate $=\mathrm{k}[\mathrm{A}]^{-1 / 2}[\mathrm{~B}]^{3 / 2}$

Question 16: Palette 16/72

NEET 2023 MCQ

For a certain reaction, the rate $=\mathrm{k}[\mathrm{A}]^{2}[\mathrm{~B}]$, when the initial concentration of A is tripled keeping concentration of $\mathrm{B}$ constant, the initial rate would

A

increase by a factor of six

B

increase by a factor of nine

C

increase by a factor of three

D

decrease by a factor of nine

Question 17: Palette 17/72

NEET 2023 MCQ

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

Assertion A : A reaction can have zero activation energy.

Reason R : The minimum extra amount of energy absorbed by reactant molecules so that their energy becomes equal to threshold value, is called activation energy.

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

A

Both A and R are true but R is NOT the correct explanation of A.

B

A is true but R is false.

C

A is false but R is true.

D

Both A and R are true and R is the correct explanation of A.

Question 18: Palette 18/72

NEET 2022 MCQ

For a chemical reaction

4A + 3B $\to$ 6C + 9D

Rate of formation of C is 6 $\times$ 10^$-$2 mol L^$-$1 s^$-$1 and rate of disappearance of A is 4 $\times$ 10^$-$2 mol L^$-$1 s^$-$1. The rate of reaction and amount of B consumed in interval of 10 seconds, respectively will be :

A

10 $\times$ 10^$-$2 mol L^$-$1 s^$-$1 and 30 $\times$ 10^$-$2 mol L^$-$1

B

1 $\times$ 10^$-$2 mol L^$-$1 s^$-$1 and 30 $\times$ 10^$-$2 mol L^$-$1

C

10 $\times$ 10^$-$2 mol L^$-$1 s^$-$1 and 10 $\times$ 10^$-$2 mol L^$-$1

D

1 $\times$ 10^$-$2 mol L^$-$1 s^$-$1 and 10 $\times$ 10^$-$2 mol L^$-$1

Question 19: Palette 19/72

NEET 2022 MCQ

The given graph is a representation of kinetics of a reaction

The y and x axes for zero and first order reactions, respectively are

A

zero order (y = concentration and x = time), first order (y = t_1/2 and x = concentration)

B

zero order (y = concentration and x = time), first order (y = rate constant and x = concentration)

C

zero order (y = rate and x = concentration), first order (y = t_1/2 and x = concentration)

D

zero order (y = rate and x = concentration), first order (y = rate and x = t_1/2)

Question 20: Palette 20/72

NEET 2022 MCQ

For a first order reaction A $\to$ Products, initial concentration of A is 0.1 M, which becomes 0.001 M after 5 minutes. Rate constant for the reaction in min^$-$1 is

A

1.3818

B

0.9212

C

0.4606

D

0.2303

Question 21: Palette 21/72

NEET 2021 MCQ

For a reaction, A $\to$ B, enthalpy of reaction is $-$4.2 kJ mol^$-$1 and enthalpy of activation is 9.6 kJ mol^$-$1. The correct potential energy profile for the reaction is shown in option.

A

B

C

D

Question 22: Palette 22/72

NEET 2021 MCQ

The slope of Arrhenius plot $\left( {\ln \,k\,v/s{1 \over T}} \right)$ of first order reactino is $-$5 $\times$ 10³K. The value of E_a of the reaction is. Choose the correct option for your answer.

[Given R = 8.314 JK^$-$1mol^$-$1]

A

$-$83 kJ mol^$-$1

B

41.5 kJ mol^$-$1

C

83.0 kJ mol^$-$1

D

166 kJ mol^$-$1

Question 23: Palette 23/72

NEET 2020 MCQ

An increase in the concentration of the reactants of a reaction leads to change in :

A

heat of reaction

B

threshold energy

C

collision frequency

D

activation energy

Question 24: Palette 24/72

NEET 2020 MCQ

The rate constant for a first order reaction is 4.606 $ \times $ 10^-3 s^-1. The time required to reduce 2.0 g of the reactant to 0.2 g is :

A

200 s

B

500 s

C

1000 s

D

100 s

Question 25: Palette 25/72

NEET 2019 MCQ

For the chemical reaction
N₂(g) + 3H₂(g) ⇌ 2NH₃(g)
the correct option is :

A

$ - {{d\left[ {{N_2}} \right]} \over {dt}} = 2{{d\left[ {N{H_3}} \right]} \over {dt}}$

B

$ - {{d\left[ {{N_2}} \right]} \over {dt}} = {1 \over 2}{{d\left[ {N{H_3}} \right]} \over {dt}}$

C

$3{{d\left[ {{H_2}} \right]} \over {dt}} = 2{{d\left[ {N{H_3}} \right]} \over {dt}}$

D

$ - {1 \over 3}{{d\left[ {{H_2}} \right]} \over {dt}} = -{1 \over 2}{{d\left[ {N{H_3}} \right]} \over {dt}}$

Question 26: Palette 26/72

NEET 2019 MCQ

If the rate constant for a first order reaction is k, the time (t) required for the completion of 99 % of the reaction is given by :

A

$t = {{4.606} \over k}$

B

$t = {{2.303} \over k}$

C

$t = {{0.693} \over k}$

D

$t = {{6.909} \over k}$

Question 27: Palette 27/72

NEET 2018 MCQ

When initial concentration of the reactant is doubled, the half-life period of a zero order reaction

A

is halved

B

is doubled

C

is tripled

D

remains unchanged.

Question 28: Palette 28/72

NEET 2018 MCQ

The correct difference between first and second order reactions is that

A

the rate of a first-order reaction does not depend on reactant concentrations; the rate of a second-order reaction does depend on reactant concentrations

B

the half-life of a first-order reaction does not depend on [A]₀ ; the half-life of a second order reaction does depend on [A]₀

C

a first-order reaction can be catalysed; a second-order reaction cannot be catalysed

D

the rate of a first-order reaction does depend on reactant concentrations; the rate of a second-order reaction does not depend on reactant concentrations

Question 29: Palette 29/72

NEET 2017 MCQ

A first order reaction has a specific reaction rate of 10^$-$2 sec^$-$1. How much time will it take for 20 g of the reactant to reduce to 5 g?

A

138.6 sec

B

346.5 sec

C

693.0 sec

D

238.6 sec

Question 30: Palette 30/72

NEET 2017 MCQ

Mechanism of a hypothetical reaction
X₂ + Y₂ $ \to $ 2XY, is given below :
(i)   X₂ $ \to $ X + X (fast)
(ii)  X + Y₂ $\rightleftharpoons$ XY + Y (slow)
(iii) X + Y $ \to $ XY (fast)
The overall order of the reaction will be

A

2

B

0

C

1.5

D

1

Question 31: Palette 31/72

NEET 2016 MCQ

The decomposition of phosphine (PH₃) on tungsten at low pressure is a first-order reaction. It is because the

A

rate is proportional to the surface coverage

B

rate is inversely proportional to the surface coverage

C

rate is independent of the surface coverage

D

rate of decomposition is very slow.

Question 32: Palette 32/72

NEET 2016 MCQ

The rate of first-order reaction is 0.04 mol L^$-$1 s^$-$1 at 10 seconds and 0.03 mol L^$-$1 s^$-$1 at 20 seconds after initiation of the reaction. The half-life period of the reaction is

A

44.1 s

B

54.1 s

C

24.1 s

D

34.1 s

Question 33: Palette 33/72

NEET 2016 MCQ

The addition of a catalyst during a chemical reaction alters which of the following quantities?

A

Enthalpy

B

Activation energy

C

Entropy

D

Internal energy

Question 34: Palette 34/72

NEET 2015 MCQ

The rate constant of the reaction A $ \to $ B is 0.6 $ \times $ 10^$-$3 mol L^$-$1 s^$-$1. If the concentration of A is 5 M, then concentration of B after 20 minutes is

A

3.60 M

B

0.36 M

C

0.72 M

D

1.08 M

Question 35: Palette 35/72

NEET 2015 MCQ

When initial concentration of a reactant is doubled in a reaction, its half-life period is not affected. The order of the reaction is

A

second

B

more than zero but less than first

C

zero

D

first.

Question 36: Palette 36/72

NEET 2015 MCQ

The activation energy of a reaction can be determined from the slope of which of the following graphs?

A

ln k vs. ${1 \over T}$

B

${T \over {\ln \,k}}$ vs. ${1 \over T}$

C

ln k vs. $T$

D

${{\ln k} \over T}$ vs. $T$

Question 37: Palette 37/72

NEET 2013 MCQ

A reaction is 50% complete in 2 hours and 75% complete in 4 hours. The order of reaction is

A

1

B

2

C

3

D

0

Question 38: Palette 38/72

NEET 2013 MCQ

For a reaction between A and B the order with respect to A is 2 and the other with respect to B is 3. The concentrations of both A and B are doubled, the rate will increase by a factor of

A

12

B

16

C

32

D

10

Question 39: Palette 39/72

NEET 2013 MCQ

What is the activation energy for a reaction if its rate doubles when the temperature is raised from 20^oC to 35^oC?
(R = 8.314 J mol^$-$1 K^$-$1)

A

34.7 kJ mol^$-$1

B

15.1 kJ mol^$-$1

C

342 kJ mol^$-$1

D

269 kJ mol^$-$1

Question 40: Palette 40/72

NEET 2012 MCQ

In a zero-order reaction, for every 10^oC rise of temperature, the rate is doubled. If the temperature is increased from 10^oC to 100^oC, the rate of the reaction will become

A

256 times

B

512 times

C

64 times

D

128 times

Question 41: Palette 41/72

NEET 2012 MCQ

In a reaction, A + B $ \to $ product, rate is doubled when the concentration of B is doubled, and rate increases by a factor of 8 when the concentration of both the reactants (A and B) are doubled, rate law for the reaction can be written as

A

rate = k[A][B]²

B

rate = k[A]²[B]²

C

rate = k[A][B]

D

rate = k[A]²[B]

Question 42: Palette 42/72

NEET 2012 MSQ

Activation energy (E_$a$) and rate constants (k₁ and k₂) of a chemical reaction at two different temperatures (T₁ and T₂) are related by

A

$\ln {{{k_2}} \over {{k_1}}} = - {{{E_a}} \over R}\left( {{1 \over {{T_1}}} - {1 \over {{T_2}}}} \right)$

B

$\ln {{{k_2}} \over {{k_1}}} = - {{{E_a}} \over R}\left( {{1 \over {{T_2}}} - {1 \over {{T_1}}}} \right)$

C

$\ln {{{k_2}} \over {{k_1}}} = - {{{E_a}} \over R}\left( {{1 \over {{T_2}}} + {1 \over {{T_1}}}} \right)$

D

$\ln {{{k_2}} \over {{k_1}}} = {{{E_a}} \over R}\left( {{1 \over {{T_1}}} - {1 \over {{T_2}}}} \right)$

Question 43: Palette 43/72

NEET 2011 MCQ

The rate of the reaction :   2N₂O₅ $ \to $ 4NO₂ + O₂
can be written in three ways.

${{ - d\left[ {{N_2}{O_5}} \right]} \over {dt}} = k\left[ {{N_2}{O_5}} \right]$

${{d\left[ {N{O_2}} \right]} \over {dt}} = k'\left[ {{N_2}{O_5}} \right];\,\,$ ${{d\left[ {{O_2}} \right]} \over {dt}} = k''\left[ {{N_2}{O_5}} \right]$

The relationship between k and k' and between k and k'' are

A

$k' = 2k ;  k'' = k$

B

$k' = 2k ;  k'' = k/2$

C

$k' = 2k ;  k'' = 2k$

D

$k' = k ;  k'' = k$

Question 44: Palette 44/72

NEET 2011 MCQ

The unit of rate constant for a zero order reaction is

A

mol L^$-$1 s^$-$1

B

L mol^$-$1 s^$-$1

C

L² mol^$-$2 s^$-$1

D

s^$-$1

Question 45: Palette 45/72

NEET 2011 MCQ

The half-life of a substance in a certain enzyme-catalysed reaction is 138 s. The time required for the concentration of the substance to fall from 1.28 mg L^$-$1 to 0.04 mg L^$-$1 is

A

414 s

B

552 s

C

690 s

D

276 s

Question 46: Palette 46/72

NEET 2011 MCQ

Which one of the following statements for the order of a reaction is incorrect?

A

Order can be determined only experimentally.

B

Order is not influenced by stoichiometric coefficient of the reactants.

C

Order of a reaction is sum of power to the concentration terms of reactants to express the rate of reaction.

D

Order of reaction is always whole number.

Question 47: Palette 47/72

NEET 2010 MCQ

The rate of the reaction, 2NO + Cl₂ $ \to $ 2NOCl is given by the rate equation rate = k[NO]²[Cl₂]. The value of the rate constant can be increased by

A

increasing the temperature

B

increasing the concentration of NO

C

increasing the concentration of the Cl₂

D

doing all of these.

Question 48: Palette 48/72

NEET 2010 MCQ

During the kinetic study of the reaction, 2A + B $ \to $ C + D, following results were obtained

Run	[A]/mol L$-$1	[B]/mol L$-$1	Initial rate of formation of D/mol L$-$1 min$-$1
I.	0.1	0.1	6.0$ \times $10$-$3
II.	0.3	0.2	7.2$ \times $10$-$2
III.	0.3	0.4	2.88$ \times $10$-$1
IV.	0.4	0.1	2.40$ \times $10$-$2

Based on the above data which one of the following is correct?

A

Rate = k[A]²[B]

B

Rate = k[A][B]

C

Rate = k[A]²[B]²

D

Rate = k[A][B]²

Question 49: Palette 49/72

NEET 2010 MCQ

For the reaction N₂O_5(g) $ \to $  2NO_2(g) + 1/2O_2(g)
the value of rate of disappearance of N₂O₅ is given as 6.25 $ \times $ 10^$-$3 mol L^$-$1 s^$-$1. The rate of formation of NO₂ and O₂ is given respectively as

A

6.25 $ \times $ 10^$-$3 mol L^$-$1 s^$-$1 and
6.25 $ \times $ 10^$-$3 mol L^$-$1 s^$-$1

B

1.25 $ \times $ 10^$-$2 mol L^$-$1 s^$-$1 and
3.125 $ \times $ 10^$-$3 mol L^$-$1 s^$-$1

C

6.25 $ \times $ 10^$-$3 mol L^$-$1 s^$-$1 and
3.125 $ \times $ 10^$-$3 mol L^$-$1 s^$-$1

D

1.25 $ \times $ 10^$-$2 mol L^$-$1 s^$-$1 and
6.25 $ \times $ 10^$-$3 mol L^$-$1 s^$-$1

Question 50: Palette 50/72

NEET 2009 MCQ

For the reaction, N₂ + 3H₂ $ \to $ 2NH₃, if
${{d\left[ {N{H_3}} \right]} \over {dt}}$ = 2 $ \times $ 10^$-$4 mol L^$-$1 s^$-$1,
the value of ${{ - d\left[ {{H_2}} \right]} \over {dt}}$ would be

A

4 $ \times $ 10^$-$4 mol L^$-$1 s^$-$1

B

6 $ \times $ 10^$-$4 mol L^$-$1 s^$-$1

C

1 $ \times $ 10^$-$4 mol L^$-$1 s^$-$1

D

3 $ \times $ 10^$-$4 mol L^$-$1 s^$-$1

Question 51: Palette 51/72

NEET 2009 MCQ

In the reaction,
BrO$_{3(aq)}^ - $ + 5Br$_{(aq)}^ - $ + 6H⁺ $ \to $ 3Br_2(l) + 3H₂O_(l).
The rate of appearance of bromine (Br₂) is related to rate of disappearance of bromide ions as

A

${{d\left[ {B{r_2}} \right]} \over {dt}} = - {5 \over 3}{{d\left[ {B{r^ - }} \right]} \over {dt}}$

B

${{d\left[ {B{r_2}} \right]} \over {dt}} = {5 \over 3}{{d\left[ {B{r^ - }} \right]} \over {dt}}$

C

${{d\left[ {B{r_2}} \right]} \over {dt}} = {3 \over 5}{{d\left[ {B{r^ - }} \right]} \over {dt}}$

D

${{d\left[ {B{r_2}} \right]} \over {dt}} = - {3 \over 5}{{d\left[ {B{r^ - }} \right]} \over {dt}}$

Question 52: Palette 52/72

NEET 2009 MCQ

For the reaction A + B $ \to $ products, it is observed that

(i)  on doubling the initial concentration of A only, the rate of reaction is also doubled and
(ii)  on doubling the initial concentration of both A and B, there is a change by a factor of 8 in the rate of the reaction.

The rate of this reaction is given by

A

rate = k[A]² [B]²

B

rate = k[A] [B]²

C

rate = k[A] [B]

D

rate = k[A]² [B]

Question 53: Palette 53/72

NEET 2009 MCQ

Half-life period of a first order reaction is 1386 seconds. The specific rate constant of the reaction is

A

0.5 $ \times $ 10^$-$2 s^$-$1

B

0.5 $ \times $ 10^$-$3 s^$-$1

C

5.0 $ \times $ 10^$-$2 s^$-$1

D

5.0 $ \times $ 10^$-$3 s^$-$1.

Question 54: Palette 54/72

NEET 2008 MCQ

The rate constants k₁ and k₂ for two different reactions are 10¹⁶ $ \cdot $ e^$-$2000/T and 10¹⁵ $ \cdot $ e^$-$1000/T, respectively.
The temperature at which k₁ = k₂ is

A

2000 K

B

${{1000} \over {2.303}}K$

C

1000 K

D

${{2000} \over {2.303}}K$

Question 55: Palette 55/72

NEET 2008 MCQ

The bromination of acetone that occurs in acid solution is represented by this equation.
CH₃COCH_3(aq) + Br_2(aq)  $ \to $
     CH₃COCH₂Br(aq) + H⁺_(aq) + Br^$-$_(aq)
These kinetic data were obtained for given reaction concentrations.

Initial concentrations, M
[CH3COCH3		[Br2]		[H+]
0.30		0.05		0.05
0.30		0.10		0.05
0.30		0.10		0.10
0.40		0.05		0.20

Initial rate, disappearance of Br2, Ms$-$1
			5.7$ \times $10$-$5
			5.7$ \times $10$-$5
			1.2$ \times $10$-$4
			3.1$ \times $10$-$4

Based on these data, the rate equation is

A

Rate = k[CH₃COCH₃][Br₂][H⁺]²

B

Rate = k[CH₃COCH₃][Br₂][H⁺]

C

Rate = k[CH₃COCH₃][H⁺]

D

Rate = k[CH₃COCH₃][Br₂]

Question 56: Palette 56/72

NEET 2007 MCQ

The reaction of hydrogen and iodine monochloride is given as :
H_2(g) + 2ICl_(g) $ \to $ 2HCl_(g) + I_2(g)
This reaction is of first order with respect to H_2(g) and ICl_(g),
following mechanisms were proposed.

Mechanism A :
     H_2(g) + 2ICl_(g) $ \to $ 2HCl_(g) + I_2(g)
Mechanism B :
     H_2(g) + ICl_(g) $ \to $ HCl_(g) + HI_(g) ; slow
     HI_(g) + ICl_(g) $ \to $ HCl_(g) + I_2(g) ; fast

Which of the above mechanism(s) can be consistent with the given information about the reaction?

A

A and B both

B

Neither A nor B

C

A only

D

B only

Question 57: Palette 57/72

NEET 2007 MCQ

In a first-order reaction A $ \to $ B, if k is rate constant and initial concentration of the reactant A is 0.5 M, then the half-life is

A

${{\log 2} \over k}$

B

${{\log 2} \over {k\sqrt {0.5} }}$

C

${{\ln 2} \over k}$

D

${{0.693} \over {0.5k}}$

Question 58: Palette 58/72

NEET 2007 MCQ

If 60% of a first order reaction was completed in 60 minutes, 50% of the same reaction would be completed in approximately
(log 4 = 0.60, log 5 = 0.69)

A

45 minutes

B

60 minutes

C

40 minutes

D

50 minutes

Question 59: Palette 59/72

NEET 2006 MCQ

For the reaction, 2A + B $ \to $ 3C + D, which of the following does not express the reaction rate?

A

$ - {{d\left[ A \right]} \over {2dt}}$

B

$ - {{d\left[ C \right]} \over {3dt}}$

C

$ - {{d\left[ B \right]} \over {dt}}$

D

$ {{d\left[ D \right]} \over {dt}}$

Question 60: Palette 60/72

NEET 2006 MCQ

Consider the reaction :  N_2(g) + 3H_2(g) $ \to $ 2NH_3(g)

The equality relationship between ${{d\left[ {N{H_3}} \right]} \over {dt}}$ and $ - {{d\left[ {{H_2}} \right]} \over {dt}}$ is

A

${{d\left[ {N{H_3}} \right]} \over {dt}} = - {{d\left[ {{H_2}} \right]} \over {dt}}$

B

${{d\left[ {N{H_3}} \right]} \over {dt}} = - {1 \over 3}{{d\left[ {{H_2}} \right]} \over {dt}}$

C

$ + {{d\left[ {N{H_3}} \right]} \over {dt}} = - {2 \over 3}{{d\left[ {{H_2}} \right]} \over {dt}}$

D

$ + {{d\left[ {N{H_3}} \right]} \over {dt}} = - {3 \over 2}{{d\left[ {{H_2}} \right]} \over {dt}}$

Question 61: Palette 61/72

NEET 2005 MCQ

The rate of reaction between two reactions A and B decreases by a factor of 4 if the concentration of reactant B is doubled. The order of this reaction with respect to reactant B is

A

2

B

$-$2

C

1

D

$-$1

Question 62: Palette 62/72

NEET 2005 MCQ

For a first order reaction A $ \to $ B the reaction rate a reactant concentration of 0.01 M is found to be 2.0 $ \times $ 10^$-$5 mol L^$-$1 s^$-$1. The half-life period of the reaction is

A

30 s

B

220 s

C

300 s

D

347 s

Question 63: Palette 63/72

NEET 2004 MCQ

The rate of a first order reaction is 1.5 $ \times $ 10^$-$2 mol L^$-$1 min^$-$1 at 0.5 M concentration of the reactant. The half-life of the reaction is

A

0.383 min

B

23.1 min

C

8.73 min

D

7.53 min

Question 64: Palette 64/72

NEET 2003 MCQ

The reaction A $ \to $ B follows first order kinetics. The time taken for 0.8 mole of A to produce 0.6 mole of B is 1 hour. What is the time taken for conversion of 0.9 mole of A to produce 0.675 mole of B?

A

1 hour

B

0.5 hour

C

0.25 hour

D

2 hours

Question 65: Palette 65/72

NEET 2003 MCQ

The temperature dependence of rate constant (k) of a chemical reaction is written in terms of Arrhenius equation, $k = A \cdot {e^{ - E{}^ * /RT}}$. Activation energy (E^{$ * $}) of the reaction can be calculated by plotting

A

$k\,\,vs\,\,T$

B

$k\,\,vs\,\,{1 \over {\log T}}$

C

$\log \,k\,\,vs\,\,{1 \over T}$

D

$\log \,k\,\,vs\,{1 \over {\log T}}$

Question 66: Palette 66/72

NEET 2003 MCQ

The activation energy for a simple chemical reaction A $\rightleftharpoons$ B is E_$a$ in forward direction.
The activation energy for reverse reaction

A

is negative of E_$a$

B

is always less than E_$a$

C

can be less than or more than E_$a$

D

is always double of E_$a$

Question 67: Palette 67/72

NEET 2003 MCQ

If the rate of the reaction is equal to the rate constant, the order of the reaction is

A

0

B

1

C

2

D

3

Question 68: Palette 68/72

NEET 2002 MCQ

2A $ \to $ B + C

It would be a zero order reaction when

A

the rate of reaction is proportional to square of concentration of A

B

The rate of reaction remains same at any concentration of A

C

the rate remains unchanged at any concentration of B and C

D

the rate of reaction doubles if concentrations of B is increased to double.

Question 69: Palette 69/72

NEET 2001 MCQ

For the reaction;

2N₂O₅ $ \to $ 4NO₂ + O₂ rate and rate constant are 1.02 $ \times $ 10^$-$4 and 3.4 $ \times $ 10^$-$5 sec^$-$1 respectively, then concentration of N₂O₅ at that time will be

A

1.732

B

3

C

1.02 $ \times $ 10^$-$4

D

3.4 $ \times $ 10⁵

Question 70: Palette 70/72

NEET 2001 MCQ

When a bio-chemical reaction is carried out in laboratory, outside the human body in absence of enzyme, then rate of reaction obtained is 10^$-$6 times, the activation energy of reaction in the presence of enzyme is

A

6/RT

B

P is required

C

different from E_$a$ obtained in laboratory

D

can't say anything.

Question 71: Palette 71/72

NEET 2000 MCQ

For the reaction H⁺ + BrO$_3^ - $ + 3Br^$-$ $ \to $ 5Br₂ + H₂O
which of the following relation correctly represents the consumption and formation of products.

A

${{d\left[ {B{r^ - }} \right]} \over {dt}} = - {3 \over 5}{{d\left[ {B{r_2}} \right]} \over {dt}}$

B

${{d\left[ {B{r^ - }} \right]} \over {dt}} = {3 \over 5}{{d\left[ {B{r_2}} \right]} \over {dt}}$

C

${{d\left[ {B{r^ - }} \right]} \over {dt}} = - {5 \over 3}{{d\left[ {B{r_2}} \right]} \over {dt}}$

D

${{d\left[ {B{r^ - }} \right]} \over {dt}} = {5 \over 3}{{d\left[ {B{r_2}} \right]} \over {dt}}$

Question 72: Palette 72/72

NEET 2000 MCQ

How enzymes increases the rate of reactions

A

by lowering activation energy

B

by increaing activation energy

C

by changing equilibrium constant

D

by forming enzyme substrate complex.