Question

$H _2 C _2 O _4$ and $NaHC _2 O _4$ behave as acids as well as reducing agents. Which of the following are correct statements?

• A. Equivalent weights of $H _2 C _2 O _4$ and $NaHC _2 O _4$ are equal to their molecular weights when acting as reducing agents
• B. Equivalent weights of $H _2 C _2 O _4$ and $NaHC _2 O _4$ are equal to half their molecular weights when acting as reducing agents
• C. $100 \,mL$ of $1 \,M$ solution of each is neutralized by equal volumes of $1 \,N\,Ca ( OH )_2$
• D. $100\, mL$ of $1 \,M$ solution of each is oxidized by equal volumes of $1 \,M\, KMO _4$

Answer 1

Answer: (B), (D)

$H _2 C _2 O _4:$ As acid, $n=2$
As reducing agent, $n=2$
$NaHC _2 O _4:$ As acid, $n=1$
As reducing agent, $n=2$
$\left.E_{ H _2 C _2 O _4}\right]_{\text {as reducing agent }}=\frac{M}{2}$;
$\left.E_{ NaHC _2 O _4}\right]_{\text {as reducing agent }}=\frac{M}{2}$
On reaction with $KMnO _4$
$H _2 C _2 O _4$ and $NaHC _2 O _4$ : both are acting as reducing
agents with same $n$ factor of 2
$mEq $ of $KMnO _4 \equiv mEq$ of $H _2 C _2 O _4$
$mEq$ of $KMnO _4 \equiv mEq$ of $NaHC _2 O _4$