Question

NaCl reacts with conc. \( H_2SO_4 \) and \( K_2Cr_2O_7 \) to give reddish fumes (B), which react with NaOH to give yellow solution (C). (B) and (C) respectively are:

• A. \(CrO_2Cl_2, Na_2CrO_4\)
• B. \(Na_2CrO_4, CrO_2Cl_2\)
• C. \(CrO_2Cl_2, KHSO_4\)
• D. \(CrO_2Cl_2, Na_2Cr_2O_7\)

Answer 1

The Correct Option is A

The reactions involved are:
NaCl + conc. H₂SO₄ + K₂Cr₂O₇ → CrO₂Cl₂ + KHSO₄ + NaHSO₄ + H₂O
(B) is CrO₂Cl₂ (reddish fumes). On reaction with NaOH, it produces a yellow solution (C) which is Na₂CrO₄:
CrO₂Cl₂ + NaOH → Na₂CrO₄ + NaCl + H₂O