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Chemical Kinetics

Short Answer Type

121. For the reaction at 500 K
${NO}_{2} (g) + CO (g) \to {CO}_{2} (g) + NO (g)$
The proposed mechanism is as follow:
(i)
${NO}_{2} + {NO}_{2} \to NO + {NO}_{3} (slow) {NO}_{3} + CO \to {CO}_{2} + {NO}_{2} (fast)$
Predict the law?

Step I:
${NO}_{2} (g) + {NO}_{2} (g) \to_{slow}^{k} {NO}_{3} (g) + NO (g)$

Step II:
${NO}_{3} (g) + CO \to {NO}_{2} (g) + {CO}_{2} (g)$

$________________________________Overall reaction : {NO}_{2} (g) + CO (g) \to NO (g) + {CO}_{2} (g)__________________________________$

Step II is much faster than step I, that is k₂>> k₁ Step I is rate determining step and thus the rate of overall reaction equals to rate of step I. Step I is is a bimolecular process that has the rate law :

rate = k_{1} {[{NO}_{2}]}^{2} .

126 Views

Long Answer Type

122. Write the overall reaction and the rate law from the following elementary reactions:

NO + {Br}_{2} ⇋ {NOBr}_{2} (fast) {NOBr}_{2} + NO \to 2 NOBr (slow)

What is the order of the reaction?

130 Views

Short Answer Type

123. Consider the reaction

A \overset{k}{\to} P .

The change in concentration of A with time is shown in the following plot:
(i) Predict the order of reaction.
(ii) Derive the expression for the time required for the completion of the reaction.

127 Views

124. Express the rate of the following reaction in terms of disappearance of the reactants and appearance of products:
PCl₅(g) → PCl₃(g) + Cl₂(g)

232 Views

125. Express the rate of the following reaction in terms of disappearance of the reactants and appearance of products:
2NO(g) + O₂(g) → 2NO₂(g)

172 Views

126. Express the rate of the following reaction in terms of disappearance of the reactants and appearance of products:
H₂(g) + l₂(g) → 2HI(g)

146 Views

127. Express the rate of the following reaction in terms of disappearance of the reactants and appearance of products:
CO(g) + NO₂(g) → CO₂(g) + NO(g)

193 Views

128. Express the rate of the following reaction in terms of disappearance of the reactants and appearance of products:
2NO₂(g) + F₂(g) → 2NO₂ F(g)

114 Views

129. The reaction:
2NO + Br₂ → 2NOBr
is supposed to follow the following mechanism.
(i)

NO + {Br}_{2} \overset{fast}{⇌} {NOBr}_{2}

(ii)

{NOBr}_{2} + NO \overset{slow}{\to} 2 NOBr

Suggest the rate law expression.

1259 Views

Long Answer Type

130. Nitric oxide, NO, reacts with oxygen to produce nitrogen dioxide,
2NO(g) + O₂(g) → 2NO₂(g)
What is the predicted rate law, if the mechanism is

247 Views

Previous Year Papers

Test Series

Test Yourself

Short Answer Type

121. For the reaction at 500 K NO2(g) + CO(g) → CO2(g) + NO(g) The proposed mechanism is as follow:(i) NO2+NO2 → NO+NO3 (slow)NO3+CO → CO2+NO2 (fast) Predict the law?

Long Answer Type

Short Answer Type

Long Answer Type

121. For the reaction at 500 K
${NO}_{2} (g) + CO (g) \to {CO}_{2} (g) + NO (g)$
The proposed mechanism is as follow:
(i)
${NO}_{2} + {NO}_{2} \to NO + {NO}_{3} (slow) {NO}_{3} + CO \to {CO}_{2} + {NO}_{2} (fast)$
Predict the law?