∑
Math
Magic
Features
Olympiad
Puzzles
Practice
Download Free
← Back to Test
Problem 3 - Olympiad
What is the oxidation state of Cr in [Cr(NH3)4Cl2]⁺?
A. +3
B. +4
C. +6
D. +2
Check Answer
Show Solution
Correct: A
Let Cr oxidation state be x. NH3 is neutral, Cl⁻ is -1 each. Total charge: x + 4(0) + 2(-1) = +1 → x = +3. Common error: Forgetting that ammonia is a neutral ligand.