Question

Moles of nitrite ions oxidized by 1 mole of permanganate ions in basic solution is given by:

• A. 2.5 moles
• B. 1 mole
• C. 3 moles
• D. 1.5 moles

Answer 1

The correct option is D 1.5 moles

Nitrite ions are oxidized by permanganate ions to form nitrate ions.

The change in the oxidation number of nitrogen is from $+3$ to $+5$. So, the valence factor is $5-3=2.$

Let the number of moles be $x$.

The valence factor for permanganate ions is $3$.

Thus by equating the equivalents for the given redox reaction,

Moles of nitrite x n factor $=$ moles of permanganate$\times n-$ factor

Moles $\times 2=1\times 3$

Thus, moles of nitrite $=\frac{3}{2}=1.5moles$