1.1. 2-methylprop-2-enenitrile has the molecular formula C₄H₅N.

Draw the displayed formula for 2-methylprop-2-enenitrile.

1.2. Two isomers of 2-methylprop-2-enenitrile, C₄H₅N, display geometric isomerism.

Draw and name the isomers.

1.3. i) Draw the repeating unit of the polymer formed by addition polymerisation of (E)-but-2-ene.

ii) Explain why the polymer formed by (E)-but-2-ene is the same as the polymer formed by (Z)-but-2-ene.

1.4. Addition polymerisation is normally an exothermic reaction. In industry, a compromise temperature of 200 $^{\circ}$C is typically used to complete the addition polymerisation process.

LDPE is produced at high temperatures and pressures while HDPE is produced at lower temperatures and pressures in the presence of a heterogeneous catalyst.

Explain how the catalyst works to reduce the reaction conditions for HDPE formation. Explain the effects of changing temperature and pressure on the yield and rate of reaction for the polymer produced from the ethene monomer.