From the following compounds how many can give positive Fehling's test

A) Acetone

B) Benzaldehyde

C) Fructose

D) Formic acid

Acetone …ketone..cannot give positive Fehling's test

Benzaldehye…aromatic aldehyde…cannot give positive Fehling's test

Fructose…monosaccharide…can give positive Fehling's test

Formicacid…contains -CHO group…can give positive Fehling's test

Fructose even though ketone undergoes reversible isomerisation in alkaline medium to form a mixture of glucose, fructose and mannose. Thus it gives positive Fehling's test.

Formic acid contains $-\stackrel{\underset{\left|\right|}{\mathrm{O}}}{\mathrm{C}}-\mathrm{H}$ group and gives positive Fehling's test.