$2 NH _{3} \rightarrow N _{2}+3 H _{2}$
Rate of formation of $N _{2}= k$
$=2 \times 10^{-4}\, mol \,L ^{-1} \,s ^{-1}$
Rate of formation of $H _{2}=3 k$
$=3 \times 2 \times 10^{-4} \,mol\, L ^{-1} \,s ^{-1}$
$=6 \times 10^{-4} \,mol \,L ^{-1}\, s ^{-1}$
$\mathrm{R}=8.314\; \mathrm{JK}^{-1} \mathrm{mol}^{-1}$
(આપેલું છે: $R =2\,cal\,K ^{-1}\,mol ^{-1}$ )