Question

Which reagent can differentiate between benzaldehyde and acetophenone?

• A. $\left[Ag\right(N{H}_3{)}_2{]}^{+}$
• B. $I_2/NaOH$
• C. Fehling's solution
• D. (a) and (b) above.

Answer 1

The correct option is D (a) and (b) above.

The iodoform reaction been used as a chemical test for the presence of a methyl ketone moiety.
Acetone and acetaldehyde have methyl ketone$(-COC{H}_3)$ moiety thus give iodoform reaction.
Benzaldehyde gives Tollen's test but acetophenone does not. On the other hand, acetophenone $(Ph-COC{H}_3$) gives iodoform test because it has methyl ketone moeity $(-COC{H}_3)$ but benzaldehyde does not because it doesnot have methyl ketone moeity $(-COC{H}_3)$. thus correct option is (d).