Chemical Kinetics - Result Question 24
####24. In the reaction, $P+Q \longrightarrow R+S$, the time taken for $75 %$ reaction of $P$ is twice the time taken for $50 %$ reaction of $P$. The concentration of $Q$ varies with reaction time as shown in the figure. The overall order of the reaction is
(2013 Adv.)
(a) 2
(b) 3
(c) 0
(d) 1
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Answer:
Correct Answer: 24. (a)
Solution:
- PLAN Time of $75 %$ reaction is twice the time taken for $50 %$ reaction if it is first order reaction w.r.t. P. From graph, $[Q]$ decreases linearly with time, thus it is zeroth order reaction w.r.t. $Q$
$$ \begin{array}{ll} & \frac{d x}{d t}=b k[P]^{a}[Q]^{b} \ \text { Order w.r.t } & P=a=1 \ \text { Order w.r.t } & Q=b=0 \end{array} $$
Thus, overall order of the reaction $=1+0=1$
