Question

Which of the following solutions will have the highest normality?

• A. 15 g of $HCl$ in 500 mL of solution
• B. 4.9 g of $H_{2}S{O}_4$ in 250 mL of solution
• C. 6.3 g of $HN{O}_3$ in 500 mL of solution
• D. 9.8 g of $H_{3}P{O}_4$ in 500 mL of solution

Answer 1

The correct option is A 15 g of $HCl$ in 500 mL of solution

(a) Gram equivalent of $HCl=\frac{\text{given mass}}{\text{equivalent mass}}=\frac{15}{36.5}=0.411$

$\text{Normality}=\frac{\text{gram equivalents of solute}}{\text{total volume of solution in mL}}\times 1000$

Normality = $\frac{0.411}{500}\times 1000=0.822$ N

(b) Gram equivalent of $H_{2}S{O}_4=\frac{\text{given mass}}{\text{equivalent mass}}=\frac{4.9}{49}=0.1$

$\text{Normality}=\frac{0.1}{250}\times 1000=0.4$ N

(c) Gram equivalent of $HN{O}_3=\frac{\text{given mass}}{\text{equivalent mass}}=\frac{6.3}{63}=0.1$

$\text{Normality}=\frac{0.1}{500}\times 1000=0.2$ N

(d) 9.8 g of $H_{3}P{O}_4$ is present in 500 mL of solution
Gram equivalent of $H_{3}P{O}_4=\frac{\text{given mass}}{\text{equivalent mass}}=\frac{9.8}{\frac{98}{3}}=0.3$

(since n – factor is 3 for $H_{3}P{O}_4$
$\text{Normality}=\frac{0.3}{500}\times 1000=0.60$ N