Question

What is the difference between the oxidation number of Mn in $KMn{O}_4$ and $M{n}_2{O}_7$?

• A. 2
• B. 5
• C. 0
• D. 3

Answer 1

The correct option is C

0

Calculate the oxidation number of Mn for both the compounds. The sum of all the oxidation numbers of all elements in a compound is zero.

Let the oxidation number of Mn in $KMn{O}_4$ be $x$ and oxidation number for $M{n}_2{O}_7$ be $y$.

The oxidation number of K is +1 and O is -2.

Hence, in $KMn{O}_4$

$+1+x+4\times (-2)=0$ which gives us $x=+7$

And in $M{n}_2{O}_7$

$2\times y+7\times (-2)=0$ which gives us $y=+7$

So the difference between the oxidation number for both the compound is $+7-(+7)=0$.

So the answer is 0.