Read the given passage and answer the questions: Zero order reactions are relatively uncommon but they occur under special conditions. Some enzyme catalysed reactions and reactions which occurs on metal surfaces are a few examples of zero order reactions. The decompositions which occurs on metal surfaces are a few examples of zero order reactions. The decomposition of gaseous ammonia on a hot platinum surface is a zero order reaction at high pressure. 2NH_(3)(g) underset("Pt catalyst") overset(1130K)to N_(2)(g)+3H_(2)(g) Rate=k[NH_(3)]^(0)=k In this reaction, Pt acts as a catalyst. At high pressure, the metal surface gets saturated with gas molecules. So a further change in reaction conditions is unable to alter the amount of ammonia on the surface of the catalyst making the rate of the reaction independent of its concentration. Q. Why is the decomposition of NH_(3) on Pt surface a zero order reaction?

Read the given passage and answer the questions: Zero order reactions

1.	Read the given passage and answer the questions: Zero order reactions are relatively uncommon but they occur under special conditions. Some enzyme catalysed reactions and reactions which occurs on metal surfaces are a few examples of zero order reactions. The decompositions which occurs on metal surfaces are a few examples of zero order reactions. The decomposition of gaseous ammonia on a hot platinum surface is a zero order reaction at high pressure. 2NH_(3)(g) underset("Pt catalyst") overset(1130K)to N_(2)(g)+3H_(2)(g) Rate=k[NH_(3)]^(0)=k In this reaction, Pt acts as a catalyst. At high pressure, the metal surface gets saturated with gas molecules. So a further change in reaction conditions is unable to alter the amount of ammonia on the surface of the catalyst making the rate of the reaction independent of its concentration. Q. Why is the decomposition of NH_(3) on Pt surface a zero order reaction?
Answer» Solution :In this reaction, Pt acts as a catalyst. At high temperature, the METAL surface gets SATURATED with gas molecules. So, a further change in reaction conditions is unable to alter the AMOUNT of AMMONIA on the surface of platinum catalyst. Thus the reaction remains independent of its concentration.