Question

Identify the formula of potassium trioxalato aluminate (III).

• A. K\(_4\)[Al(C\(_2\)O\(_4\))\(_3\)]
• B. K\(_3\)Al(C\(_2\)O\(_4\))\(_3\)
• C. Al\(_3\)[K\(_3\)(C\(_2\)O\(_4\))\(_3\)]
• D. K\(_3\)[Al(C\(_2\)O\(_4\))\(_3\)]

Hint:

In coordination complexes, the metal ion is typically enclosed in square brackets, and the counterions (like K\(^+\)) are written outside.

Answer 1

The Correct Option is D

Step 1: Understanding the complex.
Potassium trioxalato aluminate (III) consists of potassium ions (K\(^+\)) and the complex ion [Al(C\(_2\)O\(_4\))\(_3\)]\(^{3-}\), where the aluminum ion is coordinated with three oxalate (C\(_2\)O\(_4\))\(^{2-}\) ligands. The formula is K\(_3\)[Al(C\(_2\)O\(_4\))\(_3\)].

Step 2: Analyzing the options.
(A) K\(_4\)[Al(C\(_2\)O\(_4\))\(_3\)]: Incorrect — The charge on the complex would not balance.
(B) K\(_3\)Al(C\(_2\)O\(_4\))\(_3\): Incorrect — The correct formula should have the complex ion in brackets.
(C) Al\(_3\)[K\(_3\)(C\(_2\)O\(_4\))\(_3\)]: Incorrect — This formula does not represent the correct stoichiometry of the ions.
(D) K\(_3\)[Al(C\(_2\)O\(_4\))\(_3\)]: Correct — This is the correct formula for potassium trioxalato aluminate (III).

Step 3: Conclusion.
The correct answer is (D) K\(_3\)[Al(C\(_2\)O\(_4\))\(_3\)].