The rate law for the reaction below is given by the expression k[A][B] A + B → Product. If the concentration of B is increased from 0.1 to 0.3 mole, keeping the value of A at 0.1 mole, the rate constant will be:

The rate of the reaction changes with the change in the concentration of the reactant but rate constant does not get affected by it. According to the Arrhenius equation, the rate constant changes only with a change in temperature or by the effect of the catalyst. k = e-Ea/RT So D is the correct answer.