The rate of the elementary reaction at `25^@C`. `H_(2)+I_(2) to 2HI` is given by rate `=1.7 xx 10^(-18) [H_(2)] [I_(2)]`
The rate of decomposition of gaseous HI to `I_(2)" at " 25^@C` is given by rate `=2.4 xx 10^(-21) [HI]^2`.
What is the equilibrium constant for the formation of HI from `H_2 and I_2` at `25^@C?`

Explanation

`H_(2)+I_(2) underset(k_(2))overset(k_(1))Leftrightarrow 2HI`
for which `k_(1)=1.7 xx 10^(-18)`
and `k_(2)=2.4 xx 10^(-21)`
`K=k_1/k_2=(1.7 xx 10^(-18))/(2.4 xx 10^(-21))=7.08 xx 10^(2)`