NEET Chemistry Chemical Kinetics MCQs

For the reaction $2A + B \rightarrow Products$, the rate law is found to be Rate = $k[A][B]$. Which of the following mechanisms is consistent with this rate law?

The mechanism of a hypothetical reaction $A_2 + B_2 o 2AB$ is given below:

(i) $A_2 o 2A$ (fast)

(ii) $A + B_2 \rightleftharpoons AB + B$ (slow)

(iii) $A + B o AB$ (fast)

What is the overall order of the reaction?

For the reaction $2NO + O_2 o 2NO_2$, the following mechanism is proposed:

(i) $NO + O_2 \rightleftharpoons NO_3$ (fast)

(ii) $NO_3 + NO o 2NO_2$ (slow)

What is the rate law for this reaction?

In a reaction mechanism with a fast equilibrium followed by a slow step, which step determines the overall rate law?

The reaction $P + Q o R$ follows the mechanism:

(i) $P \rightleftharpoons 2X$ (fast equilibrium, K)

(ii) $X + Q o R$ (slow, k)

If the initial concentration of P is doubled while keeping the concentration of Q constant, how will the initial rate of formation of R change?

A reaction proceeds via a two-step mechanism: a fast reversible step followed by a slow step. If the overall order of the reaction is determined to be 1.5, what are possible orders of the reactants involved in the slow step?

The reaction obey I order with respect to ${{\rm{H}}_2}$ and ${\rm{ICl}}$ both

${{\rm{H}}_2}\left( {\rm{g}} \right) + 2{\rm{ICl}}\left( {\rm{g}} \right) o 2{\rm{HCl}}\left( {\rm{g}} \right) + {{\rm{I}}_2}\left( {\rm{g}} \right)$

Which of the following mechanism is in consistent with the given fact?

Mechanism$A:{{\rm{H}}_2}\left( {\rm{g}} \right) + 2{\rm{ICl}} o 2{\rm{HCl}}\left( {\rm{g}} \right) + {{\rm{I}}_2}\left( {\rm{g}} \right)$

Mechanism$B:\left( {\rm{i}} \right){{\rm{H}}_2}\left( {\rm{g}} \right) + {\rm{ICl}}\left( {\rm{g}} \right)\xrightarrow{{Slow}}{\rm{HCl}}\left( {\rm{g}} \right) + {\rm{HI}}\left( {\rm{g}} \right)$

$\left( {{\rm{ii}}} \right){\rm{HI}}\left( {\rm{g}} \right) + {\rm{ICl}}\left( {\rm{g}} \right) o {\rm{HCl}}\left( {\rm{g}} \right) + {{\rm{I}}_2}$

The rate law for the chemical reaction$2N{O_2}Cl o 2N{O_2} + C{l_2}\;is\;rate = k[N{O_2}Cl].$ The rate determining step is

Consider the reaction,

$C{l_2}\left( {aq} \right) + {H_2}S\left( {aq} \right) o S\left( s \right) + 2{H^ + }\left( {aq} \right) + 2C{l^ - }\left( {aq} \right)$ the rate equation for this reaction is , $rate = k\left[ {C{l_2}} \right]\left[ {{H_2}S} \right]$

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

$\begin{array}{l}

A.;;C{l_2} + {H_2}S\left( {aq} \right) o {H^ + }C{l^ - } + C{l^ + } + H{S^ - }\left( {slow} \right)\

;;;;;C{l^ + } + H{S^ - } o {H^ + }C{l^ - } + S\left( {fast} \right)\

B.;;{H_2}S \leftrightarrow {H^ + } + H{S^ - }\left( {fast;equilibrium} \right)\

;;;;C{l_2} + H{S^ - } o 2C{l^ - } + {H^ + }S\left( {slow} \right)

\end{array}$

For the decomposition of ${{\rm{N}}_2}{{\rm{O}}_5}$ at a particular temperature, according to the equations

$2{{\rm{N}}_2}{{\rm{O}}_5} o 4{\rm{N}}{{\rm{O}}_2} + {{\rm{O}}_2}$

${{\rm{N}}_2}{{\rm{O}}_5} o 2{\rm{N}}{{\rm{O}}_2} + \frac{1}{2}{{\rm{O}}_2}$

The activation energies are ${E_1}\;and\;{E_2}$ respectively then