Question

Identify A, B and C in the given below reaction sequence

$A \xrightarrow{HNO_3} Pb(NO_3)_2 \xrightarrow{H_2SO_4} B \xrightarrow{\begin{smallmatrix} (1) \text{ Ammonium } \\ \text{ acetate } \\ (2) \text{ Acetic acid } \\ (3) K_2CrO_4 \end{smallmatrix}}$

• A. PbCl₂, PbSO₄, PbCrO₄
• B. PbS, PbSO₄, Pb(CH₃COO)₂
• C. PbCl₂, Pb(SO₄)₂, PbCrO₄
• D. PbS, PbSO₄, PbCrO₄

Answer 1

Answer: (A)

A PbCl₂, PbSO₄, PbCrO₄

Answer 2

Explanation of the Solution:

1. Step 1: Compound A reacts with HNO₃ yielding Pb(NO₃)₂. For this to occur without redox complications, A must be a soluble salt like PbCl₂ (not PbS, which would involve oxidation).
2. Step 2: Pb(NO₃)₂ reacts with H₂SO₄ to precipitate insoluble PbSO₄ (thus B = PbSO₄).
3. Step 3: Treatment of PbSO₄ with ammonium acetate, acetic acid, and K₂CrO₄ produces yellow PbCrO₄.

Thus, A = PbCl₂, B = PbSO₄, C = PbCrO₄.