JEE CHEMISTRY MCQ: CHEMICAL KINETICS

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Which of the following is a zero order reaction?

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Correct option: A

2{\text{N}}{{\text{H}}_3}\left( {\text{g}} \right)\xrightarrow[{{\text{Pt catalyst}}}]{{1130\,{\text{K}}}}{{\text{N}}_{\text{2}}}\left( {\text{g}} \right) + 3{{\text{H}}_{\text{2}}}\left( {\text{g}} \right)

(Reactant

\mathrm{NH}_3

is strongly adsorbed

Option A (

2{\text{N}}{{\text{H}}_3}\left( {\text{g}} \right)\xrightarrow[{{\text{Pt catalyst}}}]{{1130{\,\text{K}}}}{{\text{N}}_{ ext{2}}}\left( {\text{g}} \right) + 3{{\text{H}}_{ ext{2}}}\left( {\text{g}} \right)

(Reactant

\mathrm{NH}_3

is strongly adsorbed) is correct because the decomposition of ammonia on a platinum surface at high pressure is a zero-order reaction due to the surface being saturated with ammonia.

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)

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

) The rate at which a substance reacts depends on its