The order of reaction with respect to a is 4 and with respect to b is 5 for a reaction that obeys the rate law.
The order of reaction is equal sum of power of concentration of the each reactant present in the reaction that obeys the rate law . The order of individual reactant or species present in the rate law is equal to the power of the of concentration of the respective species or reactant .
Example : If rate law is given as,
rate = k
The order of reaction with respect to a is 4 and with respect to b is 5 for a reaction that obeys the rate law.
To learn more about order of reaction please click here
#SPJ4