Question

Which of the following statements is not correct when a mixture of NaCl and K₂Cr₂O₇ is gently warmed with conc. H₂SO₄?

Options

• A deep red vapour is evolved.

• The vapour when passed into NaOH solution gives a yellow solution of Na₂CrO₄.

• Chlorine gas is evolved.

• Chromyl chloride is formed.

Answer 1

Chlorine gas is evolved.

Explanation:

When NaCl and K₂Cr₂O₇ are warmed with concentrated sulphuric acid, red vapours of chromyl chloride (CrO₂Cl₂) are formed. These vapours, when passed into NaOH, give a yellow solution of sodium chromate (Na₂CrO₄). However, no chlorine gas is evolved in this reaction.