Question

A solution is prepared by dissolving 9.8 g of $H_{2}S{O}_4$ in 54 g of water. What is the mole fraction of $H_{2}S{O}_4$ ?

• A. 0.03
• B. 0.04
• C. 0.01
• D. 0.02

Answer 1

Answer: (A)

0.03

The molecular mass of $H_{2}S{O}_4=98$

No. of moles of $H_{2}S{O}_4$ $=\frac{weight}{molecularmass}$ $=\frac{9.8}{98}=0.1$

No. of moles of water $=\frac{54}{18}=3$ (molecular weight of water=18)

Total no. of moles = 0.1 + 3 = 3.1

Therefore mole fraction$=\frac{molesof{H}_{2}S{O}_4}{Totalnumberofmoles}=\frac{0.1}{3.1}$ = 0.03

Hence, option $A$ is correct.