Question

Which one of these is the most acidic oxide?

• A. MnO (Manganese (II) oxide)
• B. Mn₂O₃ (Manganese (III) oxide)
• C. Mn₂O₇ (Manganese (VII) oxide)
• D. MnO₂ (Manganese (IV) oxide)

Hint:

Remember: The higher the oxidation state of a metal in its oxide, the more acidic the oxide is. Mn\textsuperscript{+7} in Mn\textsubscript{2}O\textsubscript{7} makes it a highly acidic oxide.

Answer 1

The Correct Option is C

Step 1: Oxide Properties and Oxidation States
An element's oxide acidity depends on its oxidation state, especially for transition metals like manganese:

• Low oxidation states: Basic or amphoteric oxides.
• High oxidation states: More acidic oxides.

Step 2: Oxidation State Analysis

• MnO: Mn (+2) ⇒ basic oxide
• Mn₂O₃: Mn (+3) ⇒ weakly basic/amphoteric
• MnO₂: Mn (+4) ⇒ amphoteric
• Mn₂O₇: Mn (+7) ⇒ strongly acidic

Step 3: Conclusion
Mn₂O₇ has manganese in the +7 oxidation state (highest). Thus, it's the most acidic oxide. \[ \boxed{\text{Mn}_2\text{O}_7 \text{ is the most acidic oxide}} \]