Question

Lower member of aldehyde is more soluble in water why?

Answer 1

Due to less steric hinderance.

Answer 2

Aldehydes and ketones are carbonyl compounds .They contain carbonyl group as a functional group which is highly polar .

Thus when dissolved in water, lower aldehydes and ketones can form hydrogen bonds with water .But as molecular mass increases,hydrophobic part in aldehydes and ketones also increases.

Due to which interaction between water molecule and molecule of aldehyde and ketone goes on decreasing. Thus solubility of aldehydes and ketones decreases with increasing molar mass or length of carbon chain