Question

Calculate normality of the solution if $5.3g$ of solid $N{a}_{2}C{O}_3$ is dissolved to make $250mL$ of the solution.

• A. $0.1N$
• B. $0.4N$
• C. $0.75N$
• D. $1N$

Answer 1

The correct option is B $0.4N$

$\text{Molecular weight of}N{a}_{2}C{O}_3=(23\times 2)+12+(3\times 16)=106gmo{l}^{-1}\text{Volume}=\frac{250}{1000}L=0.25L{n}_f=2$

Since,
$\text{Normality}=\frac{\text{Number of g-equivalents of solute}}{\text{Volume of solution (L)}}\text{Number of g-equivalents of solute}=\frac{\text{Weight of solute}}{\text{Equivalent weight of solute}}\text{Equivalent weight of solute}=\frac{\text{Molecular Mass of solute}}{\text{n-factor}}$

Putting the values we get,

$\text{Normality}=\frac{\text{Weight of solute}\times \text{n-factor}}{\text{Molecular Mass of solute}\times \text{Volume of solution (L)}}\text{Normality}=\frac{5.3g\times 2}{106gmo{l}^{-1}\times 0.25L}\text{Normality}=0.4N$