Question

Identify species having metal atom in \(+6\) oxidation state from following

• A. \(\text{MnO}_4^-\)
• B. \([\text{Cr}(\text{CN})_6]^{3-}\)
• C. \(\text{Cr}_2\text{O}_3\)
• D. \(\text{CrO}_2\text{Cl}_2\)

Hint:

Assign oxidation states using charge balance on each species.

Answer 1

The Correct Option is D

Step 1: Method
Set the sum of oxidation numbers of all atoms equal to the charge on the species.

Step 2: Check (A) and (B)
In \(\text{MnO}_4^-\): \(x + 4(-2) = -1\), so \(x = +7\). In \([\text{Cr}(\text{CN})_6]^{3-}\): \(x + 6(-1) = -3\), so \(x = +3\).

Step 3: Check (C)
In \(\text{Cr}_2\text{O}_3\): \(2x + 3(-2) = 0\), so \(x = +3\).

Step 4: Check (D)
In \(\text{CrO}_2\text{Cl}_2\): \(x + 2(-2) + 2(-1) = 0\), so \(x = +6\). This is chromyl chloride, with chromium in the +6 state.

Final Answer:
Chromium is +6 in chromyl chloride. This is option (D). \[ \boxed{\text{(D) }\text{CrO}_2\text{Cl}_2} \]