what is the order of reaction in a cannizaro reaction

since two aldehydes participate along with oh therefore the order of reaction is three 

overall the reaction is a third-order reaction. It is second order wrt aldehyde and first order wrt base:-

rate = k[RCHO]²[OH] 

however at very high base concentration a second path (k'') becomes important and it becomes second order wrt base:-

rate = k[RCHO]²[OH^-] + k''[RCHO]²[OH^-]² 

for exams generally consider the first argument i.e. it is a third order reaction

vikash kumar

Btech. IIT-Delhi