Question

Catalysts Catalysts are substances that increase the rate of reaction but can be recovered unchanged at the end of the reaction. Catalysts can be classified as either homogeneous (same state as reactants) or heterogeneous (different state than reactants).

Part A Platinum is used to catalyze the hydrogenation of ethylene: H2(g)+CH2CH2(g)−⟶Pt(s)CH3CH3(g) Chlorofluorocarbons (CFCs) catalyze the conversion of ozone (O3) to oxygen gas (O2): 2O3(g)−⟶CFC(g)3O2(g) Magnesium catalyzes the disproportionation of hydrogen peroxide to produce water and oxygen: 2H2O2(aq)−⟶Mg(s)2H2O(l)+O2(g) What type of catalysts are platinum, CFCs, and magnesium under these conditions?

Answer 1

here he has given very clearly that catalyst which is soluble in reaction medium or same as reactant then it is

homogeneous catalyst or if it is not soluble then it is heterogeneous catalyst

H2(g)+CH2CH2(g)−⟶Pt(s)CH3CH3(g)

in this reaction platinum is solide remaining all are gases means heterogeneous catalyst

2O3(g)−⟶CFC(g)3O2(g)

here all are gases including CFC so it is  homogeneous catalyst

2H2O2(aq)−⟶Mg(s)2H2O(l)+O2(g)

here Mg is solide so it is also heterogeneous catalyst