A reaction is first order in `A` secod order in `B`:
(i) write differential rate equation.
(ii) How is the rate affected when the concentration of `B` is tripled ?
(iii) How is the rate affected when the concentration of both `A` and `B` is doubled?

Answer

`a. r=k[A][B]^(2)`
`b.` Rate becomes 9 times.

Explanation

`a.` `r=k[A][B]^(2)`
`b.` `r_(2)=k[A][B]^(2)`
`r_(2)=k[A][3B]^(2)`
`(r_(2))/(r_(1))=[3]^(2),r_(2)=9r_(1)`
Rate becomes nine times.
`c.` `r_(1)=k[A][B]^(2)`
`r_(2)=k[2A][2B]^(2)`
`(r_(2))/(r_(1))=2xx(2)^(2)`
`r_(2)=8r_(1)`
Rate becomes eight times.