t some temperature, the rate constant for the reaction of the type
`2A rarr` Products
is `0.08 Ms^(-1)`. The time it takes for the concentration of A to drop from `1.50M to 0.30M` is

Options

A. `7.5s`
B. `9.5s`
C. `11.5s`
D. `13.5s`

Answer

A

Explanation

From the unit of rate constants `(molL^(-1)s^(-1))` , we can conclude that the reaction is of zero order.
For a reaction, `aArarr`products, that is zero order, the integater rate law is
`[A]_(t)=[A]_(0)-akt`
or `t=[A]_(0)-[A]_(t)//ak`
Substituting the valus, we get
`t=([(1.50)-(0.30)]M)/((2)(0.08Ms^(-1)))`
`=7.5s`