JEE CHEMISTRY MCQ: CHEMICAL KINETICS

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The reaction,

{X}+2 {Y}+{Z} \rightarrow {N}

occurs by the following mechanism :-

(i)

{X}+{Y} \rightleftharpoons {M}

very rapid equilibrium

(ii)

{M}+{Z} \rightarrow {P}

slow

(iii)

{P}+{Y} \rightarrow {N}

very fast

What is the rate law for this reaction :-

View answer and explanation

Correct option: D

Rate

={k}[{X}][{Y}][{Z}]

The correct answer is Rate = k[X][Y][Z] because the rate law is determined by the slow step in the mechanism, and the concentrations of reactants in the slow step are multiplied by the equilibrium constant of the rapid equilibrium.

More Questions from CHEMICAL KINETICS

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The reaction

\mathrm{A}_2+\mathrm{B}_2 \rightarrow 2 \mathrm{AB}

follows the mechanism

\begin{aligned} & {{\text{A}}_2}\mathop \rightleftharpoons \limits_{{{\text{k}}_{ - 1}}}^{{{\text{k}}_1}} {\text{A}} + {\text{A (fast) }} \\ & \mathrm{A}+\mathrm{B}_2 \xrightarrow{\mathrm{k}_2} \mathrm{AB}+\mathrm{B} \text { (slow) } \\ & \mathrm{A}+\mathrm{B} \rightarrow \mathrm{AB} \text { (fast) } \end{aligned}

The overall order of the reaction is: For the first order reaction with the rate constant

k

, which expression gives the rate half-life period?

(Initial\mathrm{ }conc.\mathrm{ } = a)

Which of the following is a zero order reaction? For a certain reaction involving a single reactant, it is found that

C_0 \sqrt{T}

is constant, where

C_0

is the initial concentration of the reactant and

T

is the half-life. What is the order of the reaction? Arrhenius equation is The energy of activation for an uncatalysed reaction is

100 \mathrm{~kJ/mol}.

Presence of a catalyst lowers the energy of activation by

75 \%

. The

\log _{10} \frac{K_2}{K_1}

of the ratio of rate constant of catalysed and uncatalysed reactions at

27^{\circ} \mathrm{C}

is?

Assume the frequency factor is same for both reactions. (Given

2.303 \times 8.314=19.147

)