$S{O}_2$ reacts with $O_2$as follows $2S{O}_2+O_2\to 2S{O}_{3,}$ The rate of disappearance of  $S{O}_2$is $2.4\times {10}^{-4}$ mole $li{t}^{-1}{\min }^{-1}$ then  

Rate of rection is $1.2\times {10}^{-4}$ mole $li{t}^{-1}{\min }^{-1}$

Rate of appearance of $S{O}_{3}is2.4\times {10}^{-4}moleli{t}^{-1}{\min }^{-1}$

Rate of disappearance of $O_{2}is9.2\times {10}^{-4}moleli{t}^{-1}{\min }^{-1}$

Rate of reaction is twice the rate of disappearance of $S{O}_3$