2. Heptane has 9 structurer isomers. (a) Write structures of all the nine acyclic structural isomers of heptane. (8 marks) (b) For which of the structures in (a) is stereoisomerism possible? (2 marks) (c) For each structure in (c) write all the stereoisomers and label all those related as: (i) Enantiomers. (8 marks) (ii) Diastereomers. (iii) Meso compounds.