# HI→H2 + I2 which order reaction?

Oct 15, 2016

This is a second order reaction.

#### Explanation:

For the reaction,

${\text{2HI" → "H"_2 + "I}}_{2}$,

the experimentally determined rate law is

${\text{rate" = k"[HI]}}^{2}$

The order of the reaction is the exponent in the rate law.

Thus, this is a second order reaction.