Question

Cerium (Z = 58) is an important member of the lanthanoids. Which of the following statements about Cerium is incorrect?

Options

• The common oxidation states of cerium are + 3 and + 4.

• The +3 oxidation state of cerium is more stable than the +4 oxidation state.

• The +4 oxidation state of cerium is not known in solutions.

• Cerium (IV) acts as an oxidising agent.

Answer 1

The +4 oxidation state of cerium is not known in solutions.

Explanation:

The +4 oxidation state is known in solution, especially in acidic medium (e.g., ceric sulphate).