Question

Calculate the weight of $CaC{O}_3$ required to produce a $0.5N$ of $100mL$ solution.

• A. $2.5g$
• B. $5g$
• C. $7.5g$
• D. $10g$

Answer 1

The correct option is A $2.5g$

Let the weight of $CaC{O}_3$ be $xg$.
$\text{Molecular weight of}CaC{O}_3=40+12+(3\times 16)=100gmo{l}^{-1}$
$\text{Volume}=\frac{100}{1000}L=0.1L{n}_f=2$
$\text{Normality}=\frac{\text{Number of g-equivalents of solute}}{\text{Volume of solution (L)}}$

$\text{Normality}=\frac{\text{Weight of solute}\times \text{n-factor}}{\text{Molecular Mass of solute}\times \text{Volume of solution (L)}}0.5=\frac{x\times 2}{100\times 0.1}x=2.5g$
$\therefore$ weight of $CaC{O}_3$ required is $2.5g$.