The reaction (r) $2ICl(g)+H_2(g)$ $\longrightarrow$ $ I_2(g)$ $+$ $2HCl(g)$ proceeds by two elementary steps: (a) $ICl(g)+H_2(g)$ $\longrightarrow$ $ HCl(g)$ $+$ $HI(g)$ (slow) (b) $HI(g)+ICl(g)$ $\longrightarrow$ $ HCl(g)$ $+$ $I_2(g)$ (fast)
Determine the form of the rate law of (r)!
