# How does the "normality" of an "oxalic acid" solution relate to its "molarity"?

Jul 22, 2016

This is formally twice the molar quantity.

#### Explanation:

Oxalic acid is a diacid, i.e. $H O \left(O =\right) C - C \left(= O\right) O H$. Formally each equiv of acid requires 2 equiv of base to achieve neutrality. Of course $p {K}_{a 2}$ will be substantially greater than $p {K}_{a 1}$. You should look these values up.

Jul 22, 2016

The oxalic acid is available in crystalline form having formula $H O O C - C O O H .2 {H}_{2} O$

$\text{Its molar mass"=2*12+6*16+6*1=126g/"mol}$

The basicity of this acid is 2 as its molecule produces 2 ${H}^{+}$ ions in its aqueous solution.

The equivalent mass of this acid is
$= \text{molar mass"/"basicity"=126/2=63g/"equivalent}$

Normality of a solution

$= \text{No. of gm-equivalent"/L="strength in g/L "/"equivalent mass}$

$= \text{strength in g/L "/(63g/"equivalent}$

So knowing the strength in $\frac{g}{L}$ and deviding it by $63 \frac{g}{\text{equivalent}}$ we can easily get the Normality of oxalic acid solution