List of top Chemistry Questions on Chemical Kinetics asked in JEE Main

Relation between $t_{1/2}$ & $t_{100\%}$ for zero order & Ist order reaction respectively is:

For first order reaction, rate constant at $27^{\circ} C$ and $t^{\circ} C$ are $1.5 \times 10^3$ and $4.5 \times 10^3$ respectively. If activation energy of the reaction is $60 \text{ kJmol}^{-1}$, then ($R = 8.3 \text{ Jmol}^{-1}K^{-1}$) $\ln 3 = 1.1$
Find temperature 't' (in $^{\circ} C$).

For first order reaction, rate constant at 27°C and t°C is $1.5 \times 10^3$ and $4.5 \times 10^3$ respectively. If the activation energy of the reaction is 60 kJ, then find the temperature $t$.

An organic compound undergoes first order decomposition. The time taken for decomposition to $\dfrac{1}{8}$ and $\dfrac{1}{10}$ of its initial concentration are $t_{1/8}$ and $t_{1/10}$ respectively. Find the value of \[ \frac{t_{1/8}}{t_{1/10}}\times10 \] (Given: $\log 2 = 0.3$)

The temperature at which the rate constants of the given below two gaseous reactions become equal is ____________ K (Nearest integer).
\[ X \longrightarrow Y, \qquad k_1 = 10^{6} e^{-\frac{30000}{T}} \] \[ P \longrightarrow Q, \qquad k_2 = 10^{4} e^{-\frac{24000}{T}} \] Given: $ \ln 10 = 2.303 $

Observe the following reactions at T(K).
I. $A \to$ products.
II. $5Br^- + BrO_3^- + 6H^+ \to 3Br_2 + 3H_2O$.
Both the reactions are started at 10.00 am. The rates of these reactions at 10.10 am are same. The value of $-\frac{d[Br^-]{dt}$ at 10.10 am is $2 \times 10^{-4} \text{ mol L}^{-1} \text{min}^{-1}$. The concentration of A at 10.10 am is $10^{-2} \text{ mol L}^{-1}$. What is the first order rate constant (in $\text{min}^{-1}$) of reaction I?}

For a chemical reaction : $\text{A} \rightarrow \text{D}$. Mechanism is Step-1: $\text{A} \rightarrow \text{B} : \Delta H = +\text{ve}$. Step-2: $\text{B} \rightarrow \text{C} : \Delta H = -\text{ve}$. Step-3: $\text{C} \rightarrow \text{D} : \Delta H = -\text{ve}$. Select the correct energy plot

Consider the following compounds. Arrange these compounds in a n increasing order of reactivity with nitrating mixture. The correct order is :

For a given reaction $A \rightarrow nB$, a graph is given between concentration and time. Find value of n for above reaction, based on the information given in graph for $10 \text{ min}$.

At $27^\circ\text{C}$, in presence of a catalyst, activation energy of a reaction is lowered by $10\,\text{kJ mol}^{-1}$. The logarithm of the ratio $\dfrac{k(\text{catalysed})}{k(\text{uncatalysed})}$ is ___.
(Consider that the frequency factor for both the reactions is same)

$A \rightarrow D$ is an endothermic reaction occurring in three elementary steps:
(i) $A \rightarrow B \quad \Delta H_i = +\text{ve}$
(ii) $B \rightarrow C \quad \Delta H_{ii} = -\text{ve}$
(iii) $C \rightarrow D \quad \Delta H_{iii} = -\text{ve}$
Which of the following graphs between potential energy (y-axis) versus reaction coordinate (x-axis) correctly represents the reaction profile of $A \rightarrow D$?

Given below are statements about some molecules/ions. Identify the CORRECT statements.
A. The dipole moment value of $\mathrm{NF_3}$ is higher than that of $\mathrm{NH_3}$.
B. The dipole moment value of $\mathrm{BeH_2}$ is zero.
C. The bond order of $\mathrm{O_2^{2-}}$ and $\mathrm{F_2}$ is same.
D. The formal charge on the central oxygen atom of ozone is $-1$.
E. In $\mathrm{NO_2}$, all the three atoms satisfy the octet rule, hence it is very stable.
Choose the correct answer from the options given below:

Given above is the concentration vs time plot for a dissociation reaction : $A \to nB$. Based on the data of the initial phase of the reaction (initial 10 min), the value of n is ____.

Correct statements regarding Arrhenius equation among the following are:
Factor $e^{-E_a/RT}$ corresponds to fraction of molecules having kinetic energy less than $E_a$.
At a given temperature, lower the $E_a$, faster is the reaction.
Increase in temperature by about $10^\circ\text{C}$ doubles the rate of reaction.
Plot of $\log k$ vs $\dfrac{1}{T}$ gives a straight line with slope $= -\dfrac{E_a}{R}$.
Choose the correct answer from the options given below:

Consider $ A \xrightarrow{k_1} B $ and $ C \xrightarrow{k_2} D $ are two reactions. If the rate constant ($k_1$) of the $ A \rightarrow B $ reaction can be expressed by the following equation
\[ \log_{10} k = 14.34 - \frac{1.5 \times 10^{4}}{T/K} \] and activation energy of $ C \rightarrow D $ reaction ($E_{a2}$) is $ \dfrac{1}{5} $th of the $ A \rightarrow B $ reaction ($E_{a1}$), then the value of ($E_{a2}$) is ______________ kJ mol$^{-1}$ (Nearest Integer).

$A \rightarrow \text{Product}$ (First order reaction). Three sets of experiments were performed for a reaction under similar experimental conditions: \[ \text{Run 1} \Rightarrow 100\ \text{mL of } 10\ \text{M solution of reactant } A \] \[ \text{Run 2} \Rightarrow 200\ \text{mL of } 10\ \text{M solution of reactant } A \] \[ \text{Run 3} \Rightarrow 100\ \text{mL of } 10\ \text{M solution of reactant } A + 100\ \text{mL of } H_2O \] The correct variation of rate of reaction is

Decomposition of A is a first order reaction at T(K) and is given by $ A(g) \rightarrow B(g) + C(g) $.
In a closed 1 L vessel, 1 bar A(g) is allowed to decompose at T(K). After 100 minutes, the total pressure was 1.5 bar. What is the rate constant (in $ min^{-1} $) of the reaction ? ($ \log 2 = 0.3 $)

Given at $10 \text{ AM}$, reaction is started (i) $A \xrightarrow{k} \text{Product}$ ($1^{\text{st}}$ order reaction) (ii) $BrO_3^- + 5Br^- \rightarrow 3Br_2$. At $10:10 \text{ AM}$, rate of disappearance of $Br^-$ was $2 \times 10^{-3} \text{ M/min}$ and concentration of $A$ was $0.1 \text{ M}$, if both reactions were proceed with same rate at this time then value of $k$ will be ?

Consider a first order reaction: \[ A \rightarrow \text{products} \] 3 different solutions are taken and the rate of reaction of: Solution 1: 100 mL 10M $ A $ $ \rightarrow r_1 $ Solution 2: 200 mL 10M $ A $ $ \rightarrow r_2 $ Solution 3: 100 mL 10M $ A $ + 100 mL water $ \rightarrow r_3 $ The correct order of the rates of reactions is,

For a reaction at $300 \text{ K}$, on addition of catalyst, activation energy of reaction lowered by $10 \text{ kJ}$. Then calculate the value of $\log \frac{K_{\text{catalysed}}}{K_{\text{uncatalysed}}}$

Find temperature (in Kelvin) at which rate constant are equal for the following reaction?
$\text{A $\rightarrow$ B, K = 10$^4$ e$^{-24000/T}$} $
$\text{P $\rightarrow$ Q, K = 10$^6$ e$^{-30000/T}$} $

For two chemical reactions A and B, if the difference between their activation energy is 20 kJ at 300 K (R = 8.3 J K$^{-1}$ mol$^{-1}$), determine $\dfrac{k_2}{k_1}$.

For the $1^{\text{st}}$ order decomposition reaction $\text{A} \to \text{P}$. The value of $\frac{t_{1/8}}{t_{1/10}} \times 10$ will be :-
$t_{1/8} =$ time at which concentration of A become 1/8 of initial concentration.
$t_{1/10} =$ time at which concentration of A becomes 1/10 of initial concentration.

Three experiments are running in separate vessels, following 1$^{st}$ order kinetics.
Experiment-(A) 100 ml, 10 M
Experiment-(B) 200 ml, 10 M
Experiment-(C) 100 ml, 10 M + 100 ml H$_2$O
Select correct order of rate of reaction in above experiments.

For a first order kinetics reaction, \[ \text{A} \rightarrow \text{B} + \text{C} \] If the initial pressure of A is 1 bar and at time 100 s, the total pressure is 1.5 bar, then find the rate constant of the reaction.