Question

Given below are two statements: Statement-I: [CoBr$_4$]$^{2-}$ absorbs lesser energy than [CoCl$_4$]$^{2-}$
Statement-II: [CoCl$_4$]$^{2-}$ has higher crystal field splitting energy than [CoBr$_4$]$^{2-}$

• A. Both statements-I and II are correct
• B. Both statements-I and II are incorrect
• C. Statement-I is correct and statement-II is incorrect
• D. Statement-I is incorrect and statement-II is correct

Hint:

The crystal field splitting energy is influenced by the ligand type. Strong field ligands like chloride lead to higher splitting energies compared to weaker field ligands like bromide.

Answer 1

The Correct Option is A

Step 1: Analyzing the absorption of energy.
In general, the crystal field splitting energy (CFSE) depends on the ligand and metal ion. Chloride (Cl$^-$) is a stronger field ligand than bromide (Br$^-$), meaning [CoCl$_4$]$^{2-}$ will have a higher crystal field splitting energy compared to [CoBr$_4$]$^{2-}$. As a result, [CoBr$_4$]$^{2-}$ absorbs lesser energy than [CoCl$_4$]$^{2-}$.
Step 2: Conclusion.
Both statements are correct, so the correct answer is (1).