Identify the reaction order from each of the following rate constants
`(i) k= 3 xx 10^(-5) s^(-)`
`(ii) k=9 xx 10^(-4) mol ^(-) "litre "s^(-)`
`(iii) k= 6 xx 10^(-2) ` litre `mol ^(-) s^(-)`
`(iv) k= 2.3 xx 10^(-5) L mol ^(-1) s^(-1)`
`(v) k= 3 xx 10^(-3) mol L^(-1) s^(-1)`

Answer

(i) First order (ii), (iii) and (iv) are of second order (v) Zero order
The order of a reaction can be identified from the units given for each value of k.

Explanation

The unit of rate constant, k is given as k = `(mol L^(-1))^(1-n) s^(-1)` where n is the order of the reaction. Using this relation, the unit of rate constant is found and compared with the units of k given.