Question

$138\, g$ of ethyl alcohol is mixed with $72\, g$ of water. The ratio of mole fraction of alcohol to water is

• A. 3:04
• B. 1:02
• C. 1:04
• D. 1:01

Answer 1

Answer: (A)

3:04

Answer 2

Number of moles of ethyl alcohol $=\frac{138}{46}=3$ Number of moles of water $=\frac{72}{18}=4$ $X_{C_{2}H_{5}OH}=\frac{3}{3+4}$ $=\frac{3}{7}$ $X_{H_{2}O}=\frac{4}{3+4}$ $=\frac{4}{7}$ $\frac{X_{C_{2} H_{5} O H}}{X_{H_{2} O}}=\frac{3 / 7}{4 / 7}$ $=\frac{3}{4}$