State three factors which need to be considered when an industrial catalyst is chosen. In each case explain why they are important.

This was related to assessment statement C.4.3. It proved to be challenging; candidates did not show a good understanding and answers were not well organized.

selectivity – does the catalyst give a good yield of the desired compound / OWTTE;

efficiency – how much faster does the reaction occur/reach equilibrium / OWTTE;

economic – cost / how long the catalyst will last / how easily is it poisoned / OWTTE;

environmental impact – toxicity / regeneration / recyclability/ease of separation of catalyst from reaction mixture / OWTTE;

versatility – ability to work under a range of conditions / ability to work with a range of substances / OWTTE;

Award [1 max] for any three correct factors without explanation.