State the difference between homogeneous and heterogeneous catalysts.

State one advantage and one disadvantage that homogeneous catalysts have over heterogeneous catalysts.

Advantage:

Disadvantage:

Apart from their selectivity to form the required product and their cost, discuss two other factors which should be considered when choosing a suitable catalyst for an industrial process.

homogeneous catalysts are in the same phase/state as the reactants and heterogeneous catalysts are in a different phase/state to the reactants;

Advantage

often works faster / all the catalyst is exposed to the reactants / OWTTE;

Disadvantage

difficult to remove the catalyst from the products / more limited range of acceptable catalysts;

efficiency;

ability to work under a variety of conditions;

environmental impact;

problems with the catalyst becoming poisoned (by impurities);

Most candidates correctly stated the difference between homogeneous and heterogeneous catalysts.

Most candidates could state one advantage and one disadvantage of homogeneous catalysts.

Candidates were less successful in part (c) in discussing the choice of a suitable catalyst.