Question

36 g water and 828 g ethyl alcohol form an ideal solution. The mole fraction of water in it, is:

• A. 1.0
• B. 0.7
• C. 0.4
• D. 0.1

Answer 1

Answer: (D)

Number of moles of water $(n)=\frac{36}{18}=2$ No. of moles of ethyl alcohol $(N)=\frac{828}{46}=18$ $\therefore$ Mole-fraction of water $=\frac{n}{n+N}$ $=\frac{2}{2+18}=\frac{2}{20}=0.1$