Question

Find out oxidation state of $Mn$ in acid medium.

• A. $+5$
• B. $+4$
• C. $+2$
• D. $+3$

Answer 1

Answer: (C)

$+2$

The ratio $100:33.3:20=1:\frac{1}{3}:\frac{1}{5}$

In acidic medium, the equivalent mass $=\frac{FormulamassofKMn{O}_4}{5}$
The oxidation state of Mn changes from +7 to +2.

In neutral medium, the equivalent mass $=\frac{FormulamassofKMn{O}_4}{3}$
The oxidation state of Mn changes from +7 to +4.

In alkaline medium, the equivalent mass $=\frac{FormulamassofKMn{O}_4}{1}$
The oxidation state of Mn changes from +7 to +6.