Question

Calculate mole fraction of $HCl$ in the solution of $HCl$ containing 24.8% of $HCl$ by mass.

[$H=1,Cl=35.5$]

• A. 0.2231
• B. 0.1398
• C. 0.8263
• D. 0.3485

Answer 1

Answer: (B)

0.1398

Given: the solution contains $24.8\%$ of HCl by mass.

$100$ g of solution, $24.8$ g of HCl is present.

$MolefractionofHCl=\frac{No.ofmolesofHCl}{No.ofmolesofHCl+No.ofmolesofwater}$

$=\frac{\frac{24.8}{36.5}}{\frac{24.8}{36.5}+\frac{75.2}{18}}$

$=\frac{0.68}{0.68+4.21}=\frac{0.68}{4.89}=0.139$

Hence, the correct option is $B$