Aldehydes and ketones having at least one α-hydrogen undergo aldol condensation. The compounds

(ii) 2-methylpentanal

(v)cyclohexanone

(vi) 1-phenylpropanone

(vii) phenylacetaldehyde

contain one or more α-hydrogen atoms. Therefore, these undergo aldol condensation.

Aldehydes having no α-hydrogen atoms undergo Cannizzaro reactions. The compounds

(i) Methanal

(iii)Benzaldehyde

(ix) 2, 2-dimethylbutanal

do not have any α-hydrogen. Therefore, these undergo cannizzaro reactions.

Compound (iv) Benzophenone is a ketone having no α-hydrogen atom and compound (viii) Butan-1-ol is an alcohol. Hence, these compounds do not undergo either aldol condensation or cannizzaro reactions.

Structures of the expected products of aldol condensation and Cannizzaro reaction-

Aldol condensation-

(ii) 2-methylpentanal-

(v)cyclohexanone-

(vi) 1-phenylpropanone-

(vii) phenylacetaldehyde –

Cannizzaro reaction-

(i) Methanal-

(iii) Benzaldehyde –

(ix) 2, 2-dimethylbutanal –