H}_{2}}}^{3}\times {{p}_{{{N}_{2}}}}}{{{p}_{N{{H}_{3}}}}}\] \[=\frac{{{(ATM)}^{3}}(atm)}{{{(atm)}^{2}}}={{(atm)}^{2}}\] or \[\Delta n=4-2=2\]. Unit of \[{{K}_{p}}\] for given REACTION \[={{(atm)}^{2}}\].