(i) The compound ( ) contains 2 carbon atoms which means the parent hydrocarbon is ethane. It also contains a bromo group attached to one of the carbon atoms. Thus, the nomenclature of the compound is bromoethane.

(ii) The compound () contains 1 carbon atom which means the parent hydrocarbon is methane. It also contains a functional group called aldehyde group which is represented by the adding a suffix 'al' at the end of name of the compound. Now, the name of carbon chain is modified by deleting the last 'e' of methane and adding the suffix 'al'. Thus, the nomenclature of the compound is 'methanal'.

(iii) The compound contains 6 carbon atoms which means the parent hydrocarbon is hexane. It also contains a triple bond in it which is represented by adding a suffix ‘yne’. Now, replacing the ‘ane’ of hexane by ‘yne’, the name of above compound becomes ‘hexyne’.