Question

For a reaction A + B → Product, the rate law is given by r= k[A] [B],

1. What is the order of the reaction? 

2. What will be the effect of temperature on rate constant? 

3. Can activation energy for reactions be zero? Justify your answer

Answer 1

1. Order is the sum of the powers of the concentration terms in the rate law.

 rate = K [A]^x [B]^y 

∴ Order = x + y

2. According to Arrhenius equation, at a particular temperature for a definite value of activation energy, rate constant,

k ∝ e^-1/T 

3. If average kinetic energy of reactant molecule is equal to threshold energy, then activation energy can be zero.