Question

Given below are two statements:
Statement (I) : In the Lanthanoids, the formation of Ce⁺⁴ is favoured by its noble gas configuration.
Statement (II) : Ce⁺⁴ is a strong oxidant reverting to the common +3 state.
In the light of the above statements, choose the most appropriate answer from the options given below:

• A. Both Statement I and Statement II are true
• B. Statement I is false but Statement II is true
• C. Statement I is true but Statement II is false
• D. Both Statement I and Statement II are false

Answer 1

The Correct Option is A

To solve this question, we need to examine each statement individually and determine their validity. 

1. Statement I: "In the Lanthanoids, the formation of Ce⁺⁴ is favoured by its noble gas configuration."
   • Cerium (Ce) is a lanthanide with atomic number 58. In its elemental form, it has the electron configuration: \([\text{Xe}]4f^15d^16s^2\).
   • When Ce is oxidized to Ce⁴⁺, it loses four electrons, resulting in the configuration: \([\text{Xe}]\), which is a noble gas configuration.
   • The stability of the noble gas configuration explains why Ce⁴⁺ can form under certain conditions, supporting statement I as true.
2. Statement II: "Ce⁺⁴ is a strong oxidant reverting to the common +3 state."
   • Ce⁴⁺ is indeed a strong oxidizing agent and has a tendency to revert to the more stable Ce³⁺ state.
   • Ce³⁺ is the more common oxidation state in lanthanides due to the stability of the partially filled f-orbitals.
   • This reversion process is due to the high tendency of Ce⁴⁺ to gain an electron to become Ce³⁺, making it a strong oxidant, therefore statement II is true.

Given both explanations, we conclude that both Statement I and Statement II are true. Thus, the correct option is: Both Statement I and Statement II are true.

Answer 2

\(\text{Ce}^{4+}\) has a noble gas electronic configuration, making Statement (I) true. Due to its high reduction potential, the \(\text{Ce}^{4+}/\text{Ce}^{3+}\) couple acts as a strong oxidizing agent, making Statement (II) true as well.

The correct option is (A) : Both Statement I and Statement II are true