question_answer 48)

    In which of the following reactions heterogeneous catalysis is involved? (i) (ii) (iii) (iv)         (a)'(ii), (iii)                           (b) (ii), (iii) and (iv) (c) (i), (ii) and (iii)              (d) (iv)

Answer:

                    (c)  (i) Reaction in which catalyst is in different phase than other (reactants and products) is known as heterogeneous catalysis. (ii) Here, reactant SO2 and product SO3 are in gaseous phase While platinum is in solid phase. So, this reaction represents a heterogeneous catalysis. (iii) Similarly, here N3 and Hg reactants are in gaseous phase while NH3, is in solid phase. Whereas in other reactions catalyst is in same phase with reactant(s) and product(s).