Chemical Kinetics Ques 22
22. During the kinetic study of the reaction, $2 A+B \to C+D$, following results were obtained:
| Run | $[A]/mol {~L}^{-1}$ | $[B]/mol {~L}^{-1}$ | Initial rate of formation of $D/mol {~L}^{-1} min^{-1}$ |
|---|---|---|---|
| I | 0.1 | 0.1 | $ 6.0 \times 10^{-3} $ |
| II | 0.3 | 0.2 | $ 7.2 \times 10^{-2} $ |
| III | 0.3 | 0.4 | $ 2.88 \times 10^{-1} $ |
| IV | 0.4 | 0.1 | $ 2.40 \times 10^{-2} $ |
Based on the above data which one of the following is correct?
[2010]
(a) $rate=k[A]^{2}[B]$
(b) rate $=k[A][B]$
(c) $rate=k[A]^{2}[B]^{2}$
(d) $rate=k[A][B]^{2}$
Show Answer
Answer:
Correct Answer: 22.(d)
Solution:
(d) In case of (II) and (III), keeping concentration of $[A]$ constant, when the concentration of $[B]$ is doubled, the rate quadruples. Hence, it is second order with respect to B. In case of I & IV, keeping the concentration of [B] constant, when the concentration of $[A]$ is increased four times, rate also increases four times. Hence, the order with respect to $A$ is one. hence
$ \text{ Rate }=k[A][B]^{2} $
BETA
