Draw the structures for the following compounds.
(i) Ethanoic acid , (ii) Bromopentane
(iii) Butanone , (iv) Hexanal

Explanation

The structures for ethanoic acid, bromopentane, butane and hexanal are given below:
(i) `H-underset("Ethanoic acid")underset(H)underset(|)overset(H) overset(|)(C)-overset(O)overset(||)C-OH` (ii) `H-underset(H)underset(|)overset(H)overset(|)(C)-underset("Bromopentane") underset(H)underset(|)overset(H)overset(|)(C)-underset (H)underset(|)overset(H)overset(|)(C)-underset(H)underset(|)overset(H)overset(|)(C)-underset(H)underset(|)overset(H)overset(|)(C)-Br`
(iii) `underset("Butanone")(H-underset(H)underset(|)overset(H)overset()(C)-underset(H)underset(|)overset(H)overset(|)(C)-overset(O)overset(||)(C)-underset(H)underset(|)overset(H)overset(|)(C)-H)` (iv) `underset("Hexanal")(H-underset(H)underset(|)overset(H)overset(|)(C)-underset(H)underset(|)overset(H)overset(|)(C)-underset(H)underset(|)overset(H)overset(|)(C)-underset(H)underset(|)overset(H)overset(|)(C)-underset(H)underset(|)overset(H)overset(|)(C)-overset(O)overset(||)C-H)`
Yes structural isomers are possible for bromopentane. Depending upon whether bromine atom is attached to carbon atom number 1,2 or 3 bromopentane can have three structural isomers : 1-bromopentane, 2-bromopentane and 3-brompoentane. These isomers are shown below:
`underset(1-"bromopentane")(H-underset(H)underset(|)overset(H)overset(|)(C)-underset(H)underset(|)overset(H)overset(|)(C)-underset(H)underset(|)overset(H)overset(|)(C)-underset(H)underset(|)overset(H)overset(|)(C)-underset(H)underset(|)overset(H)overset(|)(C)-Br)` `underset(2-"bromopentane")(H-underset(H)underset(|)overset(H)overset(|)(C)-underset(H)underset(|)overset(H)overset(|)(C)-underset(H)underset(|)overset(H)overset(|)(C)-underset(H)underset(|)overset(Br)overset(|)(C)-underset(H)underset(|)overset(H)overset(|)(C)-H)` `underset(3-"bromopentane")(H-underset(H)underset(|)overset(H)overset(|)(C)-underset(H)underset(|)overset(H)overset(|)(C)-underset(H)underset(|)overset(Br)overset(|)(C)-underset(H)underset(|)overset(H)overset(|)(C)-underset(H)underset(|)overset(H)overset(|)(C)-H)`