The reaction 2NO+Br2→2NOBr
takes place through the mechanism given below:
NO+Br2⇌NOBr2 (fast)
NOBr2+NO→2NOBr (slow)
The overall order of the reaction is ________ . [2023]
(3)
2NO+Br2⟶2NOBr
(i) NO+Br2⇌k2k1NOBr2 Fast
(ii) NOBr2+NO→k3slow2NOBr r=k3[NOBr2][NO] ...(i)
Keq=k1k2=[NOBr2][NO][Br2] ⇒ [NOBr2]=k1×[NO][Br2]k2
Now put [NOBr2] in equation (i) we get,
r=k1k3k2[NO]2[Br2] r=k[NO]2[Br2]
So, overall order of reaction =2+1=3.