Chemical Kinetics — JEE Main PYQs

For the reaction $2A+3B+\frac{3}{2}C\to 3P$, which statement is correct?

The rate of a reaction decreased by 3.555 times when the temperature was changed from $40^{\circ }\mathrm{C}$ to $30^{\circ }\mathrm{C}$. The activation energy (in $\mathrm{kJ}{\mathrm{mol}}^{-1}$) of the reaction is ____.

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 …

Consider the following reactions
$\mathrm{A}\to \mathrm{P}1;\mathrm{B}\to \mathrm{P}2;\mathrm{C}\to \mathrm{P}3;\mathrm{D}\to \mathrm{P}4$,
The order of the above reactions are $\mathrm{a},\mathrm{b},\mathrm{c}$ and d , respecti …

For the equilibrium $\mathrm{A}\rightleftharpoons \mathrm{B}$, the variation of the rate of the forward (a) and reverse (B) reaction with time is given by:

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: …

The number of molecules with energy greater than the threshold energy for a reaction increases five fold by a rise of temperature from $27^{\circ }\mathrm{C}$ to $42^{\circ }\mathrm{C}$. Its energy of activation in $\mathrm{J}/\mathrm{mol}$ is ............. (Take in …

For the reaction $2\mathrm{A}+\mathrm{B}\to \mathrm{C}$, the values of initial rate at different reactant concentrations are given in the table below: The rate law for the reaction is:

| $[\mathrm{A}]({\mathrm{molL}}^{-1})$ | $[\mathrm{B}]({\mathrm{molL}}^{-1})$ | Initial …

For a reaction scheme. $A\stackrel{k_1}{\to }B\stackrel{k_2}{\to }C$ if the rate of formation of $B$ is set to be zero then the concentration of $B$ is given by

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:

Consider the given plots for a reaction obeying Arrhenius equation $\left(0^{\circ }\mathrm{C}<\mathrm{T}<300^{\circ }\mathrm{C}\right)$ : ( k and ${\mathrm{E}}_{\mathrm{a}}$ are rate constant and activation energy respectively)

Choose the correct option:

The reaction $2X\to B$ is a zeroth order reaction. If the initial concentration of $X$ is $0.2M$, 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:

In the following reaction; $xA⟶yB$
${\log }_{10}\left[-\frac{\mathrm{d}[\mathrm{A}]}{\mathrm{dt}}\right]={\log }_{10}\left[\frac{\mathrm{d}[\mathrm{B}]}{\mathrm{dt}}\right]+0.3010$
'A' and 'B' respectively can be :

For the re action of ${\mathrm{H}}_2$ with ${\mathrm{I}}_2$, the rate constant is $2.5\times 10^{-4}{\mathrm{dm}}^3{\mathrm{mol}}^{-1}{\mathrm{s}}^{-1}$ at $327^{\circ }\mathrm{C}$ and $1.0{\mathrm{dm}}^3{\mathrm{mol}}^{-1}{\mathrm{s}}^{-1}$ at …

If a reaction follows the Arrhenius equation, the plot Ink $\vee 1/(\mathrm{RT})$ gives straight line with a gradient ( -y ) unit. The energy required to activate the reactant is:

Decomposition of $X$ exhibits a rate constant for $0.05\mu$g/year. How many years are required for the decomposition of $5\mu$g of X into $2.5\mu$g?

${\mathrm{NO}}_2$ required for a reaction is produced by the decomposition of ${\mathrm{N}}_2{\mathrm{O}}_5$ in ${\mathrm{CCl}}_4$ as per the equation
$2{\mathrm{N}}_2{\mathrm{O}}_5(\mathrm{g})\to 4{\mathrm{NO}}_2(\mathrm{g})+{\mathrm{O}}_2(\mathrm{g})$
T …

For a certain reaction consider the plot of $\ell \mathrm{nk}$ versus $1/\mathrm{T}$ given in the figure. If the rate constant of this reaction at 400 K is $10^{-5}{\mathrm{s}}^{-1}$, then the rate constant at 500 K is:
$\ln \mathrm{k}$ Slope $=-4606\mathrm{K}$

Consider the given plot of enthalpy of the following reaction between A and B .

Identify the incorrect statement

For the reaction, $2\mathrm{A}+\mathrm{B}⟶$ products , when the concentrations of A and B both were doubled, the rate of the reaction increased from $0.3\mathrm{mol}{\mathrm{L}}^{-1}{\mathrm{s}}^{-1}$ to …

The following results were obtained during kinetic studies of the reaction $2\mathrm{A}+\mathrm{B}⟶$ products

| Experiment | $[\mathrm{A}]$ (in mol L${}^{-1}$) | $[\mathrm{B}]$ (in mol L${}^{-1}$) | Initial rate of reaction (in …

A bacterial infection in an internal would grows as ${\mathrm{N}}^{\prime }(\mathrm{t})={\mathrm{N}}_0\exp (\mathrm{t})$, where the time t is in hours. A dose of antibiotic, taken orally, needs 1 hour to reach the wound. Once it reaches there, the bacterial population goes down a …

At $518^{\circ }\mathrm{C}$, the rate of decomposition of a sample of gaseous acetaldehyde, initially at a pressure of 363 Torr, was 1.00 Torr ${\mathrm{s}}^{-1}$ when $5\%$ had reacted and 0.5 Torr ${\mathrm{s}}^{-1}$ when $33\%$ had reacted. The order of the reaction is …

Two reactions $R_1$ and $R_2$ have identical pre-exponential factors. Activation energy of $R_1$ exceeds that of $R_2$ by $10\mathrm{kJ}{\mathrm{mol}}^{-1}$. If ${\mathrm{k}}_1$ and ${\mathrm{k}}_2$ are rate constants for reactions $R_1$ and $R_2$ …

Decomposition of ${\mathrm{H}}_2{\mathrm{O}}_2$ follows a first order reaction. In fifty minutes the concentration of ${\mathrm{H}}_2{\mathrm{O}}_2$ decreases from 0.5 to 0.125 M in one such decomposition. When the concentration of ${\mathrm{H}}_2{\mathrm{O}}_2$ reaches …

Higher order (>3) reactions are rare due to:

For the non-stoichiometric reaction 2A + B → 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⁻¹s⁻¹) ||---------------------------|-------- …

The rate of a reaction doubles when its temperature changes from 300 K to 310 K. Activation energy of such a reaction will be:
( $\mathrm{R}=8.314{\mathrm{JK}}^{-1}{\mathrm{mol}}^{-1}$ and $\log 2=0.301$ )

For a first order reaction, $(\mathrm{A})\to$ 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 :

The rate of a chemical reaction doubles for every $10^{\circ }\mathrm{C}$ rise of temperature. If the temperature is raised by $50^{\circ }\mathrm{C}$, the rate of the reaction increases by about :

The time for half life period of a certain reaction $\mathrm{A}\to$ products is 1 hour. When the initial concentration of the reactant ' $A$ ', is $2.0\mathrm{mol}{\mathrm{L}}^{-1}$, how much time does it take for its concentration to come from 0.50 to …

Consider the reaction:
${\mathrm{Cl}}_2(\mathrm{aq})+{\mathrm{H}}_2\mathrm{S}(\mathrm{aq})\to \mathrm{S}(\mathrm{s})+2{\mathrm{H}}^{+}(\mathrm{aq})+2{\mathrm{Cl}}^{-}(\mathrm{aq})$
The rate equation for this reaction is rate …

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 ( $\log 2=0.301$ ) :

For a reaction $\frac{1}{2}A\to 2B$, rate of disappearance of ' $A$ ' is related to the rate of appearance of ' $B$ ' by the expression

The energies of activation for forward and reverse reactions for $A_2+B_2\rightleftharpoons 2AB$ are $180{\mathrm{kJ}\mathrm{mol}}^{-1}$ and $200{\mathrm{kJ}\mathrm{mol}}^{-1}$ respectively. The presence of catalyst lowers the activation energy of both (forward and reverse) reactions by …

Consider the reaction, $2\mathrm{A}+\mathrm{B}\to$ 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

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?

Which of the following nuclear reactions will generate an isotope?

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

In the transformation of ${}_{92}^{238}\mathrm{U}$ to ${}_{92}^{234}\mathrm{U}$, if one emission is an $\alpha$-particle, what should be the other emission(s)?

Rate of a reaction can be expressed by Arrhenius equation as:
$\mathrm{k}=\mathrm{A}{\mathrm{e}}^{-\mathrm{E}/\mathrm{RT}}$
In this equation, E represents

The following mechanism has been proposed for the reaction of NO with ${\mathrm{Br}}_2$ to form NOBr :
$\mathrm{NO}(\mathrm{g})+{\mathrm{Br}}_2(\mathrm{g})\rightleftharpoons {\mathrm{NOBr}}_2(\mathrm{g})$ …

Consider an endothermic reaction, $X⟶Y$ with the activation energies $E_b$ and $E_f$ for the backward and forward reactions, respectively. In general

A reaction involving two different reactants can never be

The photon of hard gamma radiation knocks a proton out of ${}_{12}^{24}\mathrm{Mg}$ nucleus to form

$t_{1/4}$ can be taken as the time taken for the concentration of a reactant to drop to $\frac{3}{4}$ of its initial value. If the rate constant for a first order reaction is K , the $t_{1/4}$ can be written as

In 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

The rate equation for the reaction $2\mathrm{A}+\mathrm{B}⟶\mathrm{C}$ is found to be: rate $=\mathrm{k}[\mathrm{A}][\mathrm{B}]$. The correct statement in relation to this reaction is that the

Consider the following nuclear reactions …

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