1. Give an explanation as to why pyridine is more basic than pyrrole . Your Answer should commence from the point of hybridization of the atoms.

2. Diatomic reactant, X2 shows both physisorption and chemisorption on to a solid absorbent, W under two different conditions. These adsorbed reactants can react with a second reactant Y to produce a product XY. The equation for this process in the presence of solid W is given below. Powder of solid W act as a catalyst for production of XY. X2 + 2Y 2XY a) Briefly explain the differences between physisorption and chemisorption processes. (20 marks) b) Draw the energy variation of both physisorption and chemisorption processes of X2 adsorption to the solid W on a Lennard-Jones potential energy diagram. Draw both energy curves on the same diagram and label the following energy values. i) Dissociation energy of X2 ii) Heats of physisorption and chemisorption (30 marks) c) Using the Lennard-Jones potential energy diagram drawn in part (b) explain how W can act as a catalyst to reduce the activation energy of XY production. (10 marks) d) Out of many catalytic parameters, selectivity is the most important parameter to determine the suitability of a catalyst. Briefly explain reasons for this selection (3-4 lines). (10 marks) e) XY can be converted to PQ using an enzyme "Z-cat" (molecular weight 30 000 g mol-1). A weight of 1.5 g from Z-cat can convert 3 moles of XY to PQ in every minute. "Z-cat" has a life time of 2 hours. Each "Z-cat" molecule has one active site that can bind with XY molecules. i) Calculate the turnover frequency of the Z-cat enzyme. ii) Calculate the turnover number of the Z-cat enzyme. (30 marks)