Ethene is one of the major products of this process and much of it is converted to polyethene using the Ziegler-Natta process. State the catalysts used and the ways in which the conditions of this process differ from the free-radical polymerization process.

catalyst of \({\text{TiC}}{{\text{l}}_{\text{4}}}{\text{/TiC}}{{\text{l}}_{\text{3}}}\) and \({\text{Al(}}{{\text{C}}_{\text{2}}}{{\text{H}}_{\text{5}}}{{\text{)}}_{\text{3}}}\);

lower temperature and lower pressure;

Accept converse argument – higher temperature and pressure required in freeradical polymerization.

This part was very poorly answered. None of the candidates scored full marks in (a), in some rare cases the mark for catalytic cracking was scored. In (b) also it was rare to see correct answers regarding Ziegler-Natta process.