• # question_answer In the reversible reaction,$2N{{O}_{2}}{{N}_{2}}{{O}_{4}}$the rate of disappearance of $N{{O}_{2}}$ is equal to A) $\frac{2{{k}_{1}}}{{{k}_{2}}}{{[N{{O}_{2}}]}^{2}}$                      B) $2{{k}_{1}}{{[N{{O}_{2}}]}^{2}}-2{{k}_{2}}[{{N}_{2}}{{O}_{4}}]$ C) $2{{k}_{1}}{{[N{{O}_{2}}]}^{2}}-{{k}_{2}}[{{N}_{2}}{{O}_{4}}]$ D) $(2{{k}_{1}}-{{k}_{2}})[N{{O}_{2}}]$

 $2N{{O}_{2}}\underset{{{k}_{2}}}{\overset{{{k}_{1}}}{\longleftrightarrow}}{{N}_{2}}{{O}_{4}}$ Rate of reaction of $=-\frac{1}{2}\frac{d\,[N{{O}_{2}}]}{dt}$ $={{k}_{1}}{{[N{{O}_{2}}]}^{2}}-{{k}^{2}}[{{N}_{2}}{{O}_{4}}]$ $\therefore \,$ Rate of disappearance of $N{{O}_{2}}$ i.e. $\frac{-d[N{{O}_{2}}]}{dt}=2{{k}_{1}}{{[N{{O}_{2}}]}^{2}}-2{{k}_{2}}[{{N}_{2}}{{O}_{4}}]$