Question

Cerium `(Z= 58)` is an important nember of the lanthanoids . Which of the following statements about cerium is incorrect ?
A. The common oxidation state of cerium are `+3` and `+4`
B. The `+3` oxidation state of cerium is more stable than `+4` oxidation state.
C. The `+4` oxidation state of cerium is not known in solution.
D. Cerium (Iv) acts as an oxidising agent.

Answer 1

Correct Answer - 3
(3) Cerium can also show the oxidation state of `+4` in solution as it leads to a noble gas configuration, from `[Xe]^(54) 4f^(1) 5d^(1) 6s^(2)` to `[Xe]^(54)`, after losing four electrons. It is only `Ce^(4+)` which exits in solution among the lanthanides.