Question

What happens, when – (Give chemical equations only) 
(i) Acetaldehyde reacts with Tollen’s reagent. 
(ii) Formaldehyde reacts with NaOH. 
(iii) Benzamide undergoes acidic hydrolysis. 
 

Hint:

- Tollen’s test $\to$ aldehydes form silver mirror.
- Cannizzaro reaction occurs with aldehydes having no $\alpha$-H.
- Amides hydrolyze to acids + ammonium salts in acidic medium.

Answer 1

(i) Acetaldehyde with Tollen’s reagent:
\[ CH_3CHO + 2[Ag(NH_3)_2]^+ + 3OH^- \;\; \longrightarrow \;\; CH_3COO^- + 2Ag \downarrow + 4NH_3 + 2H_2O \] (ii) Formaldehyde with NaOH (Cannizzaro reaction):
\[ 2HCHO + NaOH \;\; \longrightarrow \;\; HCOONa + CH_3OH \] (iii) Acidic hydrolysis of Benzamide:
\[ C_6H_5CONH_2 + H_2O + HCl \;\; \longrightarrow \;\; C_6H_5COOH + NH_4Cl \] Final Answer:
(i) Acetaldehyde $\to$ Acetate ion + Silver mirror.
(ii) Formaldehyde $\to$ Sodium formate + Methanol.
(iii) Benzamide $\to$ Benzoic acid + Ammonium chloride.