Question

The mole fraction of $HN{O}_3$ in an aqueous binary solution is $0.15$> The ratio of moles of $HN{O}_3$ to $H_{2}O$ in the solution is nearly:

• A. $17:3$
• B. $3:17$
• C. $1:1$
• D. $15:100$

Answer 1

The correct option is B $3:17$

Mole fraction of $HN{O}_3=\frac{M_{HN{O}_3}}{M_{HN{O}_3}+M_{H_{2}O}}=\frac{0.15}{1}$

$\therefore \frac{M_{HN{O}_3}}{M_{H_{2}O}}=\frac{0.15}{1-0.15}=\frac{0.15}{0.85}=\frac{3}{17}$