1. How to arrive at the rate expression for first order reaction theoretically and experimentally? 2. Clarify with neat diagram, when every collision between reactants leads to a reaction? What will happen if there is no effective collision and low activation energy of reactants? 3. How do you find the activation energy from an Arrhenius plot? In what way is this energy related to the activated complex of the reaction? 4. Enzyme-catalyzed reactions are highly unique with respect to their selectivity. Elaborate on their selectivity with detailed mechanism