Question

Highest oxidation numbers for chromium and manganese:

• A. +6, +6
• B. +6, +7
• C. +7, +6
• D. +5, +7

Hint:

The highest oxidation state for chromium is +6 and for manganese is +7, seen in compounds like CrO\(_3\) and KMnO\(_4\), respectively.

Answer 1

The Correct Option is B

Step 1: Oxidation numbers of chromium and manganese.
Chromium (Cr) can have an oxidation number of +6 in compounds like CrO\(_3\) (chromium trioxide). Manganese (Mn) can have an oxidation number of +7 in compounds like KMnO\(_4\) (potassium permanganate).
Step 2: Conclusion.
Thus, the highest oxidation numbers are +6 for chromium and +7 for manganese, which corresponds to option (B).

Answer 2

Step 1: Chromium reaches its highest oxidation number, +6, in compounds like CrO₃.

Step 2: Manganese reaches its highest, +7, in compounds like KMnO₄.

Step 3: So the highest oxidation numbers are +6 for chromium and +7 for manganese — option (B).

Answer 3

Group-number shortcut: A simple trend for the earlier transition series is that the maximum possible oxidation state often equals the element's group number. Chromium sits in group 6, so its ceiling is +6, seen in chromium trioxide and dichromate. Manganese sits in group 7, so its ceiling is +7, seen in potassium permanganate. That directly gives +6 for chromium and +7 for manganese, option (B), without checking individual compounds one by one.