Which structural feature will differ among an ester, an alcohol, and an aldehyde, regardless of which examples are being compared? the functional group the branching pattern of the carbon chain the number of carbon atoms

The functional group

Explanation:

A functional group defines a hydrocarbon. an ester the functional group is an O- alkyl group while that one of an alcohol is -OH group. An aldehyde is a functional group on its own.

the functional group

Explanation:

Functional groups are specific group of atoms within molecules that are responsible for the characteristic chemical reactions of those molecules.

1. Esters have functional group .

Example: methyl ethanoate with molecular formula

2. Alcohols have functional group .

Example: Propanol with molecular formula

3. Aledydes have functional group .

Example: propanal with molecular formula

Thus esters , alcohols and aldehydes may have same number of carbon atoms and similar branching pattern but different functional groups.

c is the answer because when something is left after something evaporates that shows the chemical change.