Identify the order for the following reactions
(i) Rusting of Iron
(ii) Radioactive disintegration of `""_(92)U^(238)`
(iii) `2A+B to ` products, rate`=k[A]^(1//2)[B]^(2)`

Explanation

`1Fe+underset(("excess"))(3O_(2)) overset(H_(2)O"(excess)") to 2Fe_(2)O_(3). xH_(2)O`
Theoritically order value may be more than one but practically one.
(ii) All radioactive disintegrations are first order reactions
(iii) `2A+3B to ` products
rate `=k[A]^(1//2)[B]^(2)`
Order `=(1)/(2)+2=(5)/(2)=2.5`