• # question_answer The equilibrium constant for the reactions (i) ${{N}_{2}}+{{O}_{2}}\rightleftharpoons \,2NO$ and (ii) $2NO+{{O}_{2}}\rightleftharpoons 2N{{O}_{2}}$ are ${{K}_{1}}$ and ${{K}_{2}}$ respectively, then what will be the equilibrium constant for the reaction ${{N}_{2}}+2{{O}_{2}}\rightleftharpoons 2N{{O}_{2}}?$

Adding eqns. (i) and (ii), we get the required equation. Thus, (i) and (ii) are the two steps of the required equation. Hence, for the required reaction, $K={{K}_{1}}\times {{K}_{2}}$.