In the reaction, `P+Q rarr 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

Options

A. 2
B. 3
C. 0
D. 1

Answer

D

Explanation

For the reaction,
`P+QrarrR+S`
The rate law is
Rate `=k[P]^(x)[Q]^(y)`
Since `t_(75%)=2t_(50%)` , the half-life is independent of initial concentration of `P` (`75%` means two half-lives). Thus, it is a first order reaction with resepect to `P`
Since plot of `|Q|` against time `(t)` is a straight line, order or reaction with respect to `Q` is zero. Thus, the rate law is
Rate `=k[P]^(1)[Q]^(@)`
Hence, the overall order of the reaction is one.