Question

The half period for the decomposition of a compound is 20 minutes. If the initial concentration is made twice, the half life period becomes 10 minutes. Calculate the order of reaction.

Answer 1

`t_(1//2) propto 1/([A_(0)])^(n-1)`
`(t_(1//2))_(1)/(t_(1//2))_(2) = {([A_(0)]_(2))/([A_(0)]_(1))}^(n-1)`
`20/10 = ((2a)/(a))^(n-1)` or `(2)^(1) =(2)^(n-1)` or `(2)^(1) = (2)^(n-1)`
`therefore n-1 = 1` or n=2 (second order)