AP EAMCET Engineering 18 Sep 2020 Shift 2 Paper

In this question, we have to assume that order of the reaction, xA+yB→zC with respect to B is zero, i.e., y=0.
So, the rate expression becomes,
r=k[A]x[B]y=k[A]x[B]0=k[A]x
Now, according to question
If the concentration of A is tripled, rate of reaction increased by 27 times over the initial hence.
According to available data,
(27r)=k[3A]x
x=3 and this order of reaction =3
Now, for a third order reaction half-life will be
t1/2=‌

3

2k3a02

or t1/2∝‌

1

a02