Question

Statement-I : CrO₃ is a strong oxidising agent

Statement-II : Cr⁺⁶ is more stable than Mo⁺⁶

considering the above statements, choose the correct option.

(1) Both statement-I and Statement-II are correct

(2) Both statement-I and Statement-II are incorrect

(3) Statement-I is correct but Statement-II is incorrect

(4) Statement-I is incorrect but Statement-II is correct

Answer 1

Correct option is : (3) Statement-I is correct but Statement-II is incorrect

CrO₃ is a strong oxidising agent and itself is reduced to Cr³⁺ which is more stable than Cr⁶⁺ because Cr³⁺ has stable electronic configuration.

\(\text{Cr}^{+6} + 3\text{e} \rightarrow \text{Cr}^{+3}\)

\(\text{Cr}^{+3} : 3\text{d}^3 \ \text{or}\ t _{2g}^{3}e_{g}^{0}\)

\(\therefore\) Statement-I is correct.

Stability of +6 state in group-6 increases down the group. Therefore, Mo⁺⁶ is more stable than Cr⁺⁶. So, statement-II is incorrect.