When diluted $\mathrm{H}_2 \mathrm{SO}_4$ is added to aqueous solution of potassium chromate, yellow colour solution turns to orange colour. This signifies that

• A

  chromate ions are reduced.
• B

  chromate ions are oxidised.
• Correct answer
  C

  monocentric complex is converted into dicentric complex.
• D

  oxygen gel removed from chromate ions.

Solution

On acidification of potassium chromate solution, yellow colour changes to orange due to reformation of dichromate. This suggests that monocentric complex, i.e., potassium monochromate is converted into dicentric complex, i.e. potassium dichromate. The complete reaction is as follows.

Hence, the correct answer is option: 'C'.