Question

What is oxidation number for Mn in Mn2O7 ( sign and number)

Answer 1

Answer : The oxidation number of sulfur (Mn) is, (+7)

Explanation :

Oxidation number : It represent the number of electrons lost or gained by the atoms of an element in a compound.

It is generally written with the sign (+) and (-) first and then the magnitude.

When the atoms are present in their elemental state then the oxidation number will be zero.

The oxidation number of  oxygen (O)  in compounds is usually -2.

The given compound is, $Mn_2O_7$

Let the oxidation state of Mn be, 'x'

$2x+7(-2)=0\\\\2x-14=0\\\\x=\frac{+14}{2}\\\\x=+7$

Therefore, the oxidation number of sulfur (Mn) is, (+7)

Answer 2

The oxidation number for Mn in Mn2O7 is +7. The oxidation number of manganese (Mn) in potassium permanganate (KMnO4) is +5.