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

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: 4 (B) 1: 2 (C) 1: 4 (D) 1: 1

Tardigrade Admin · Accepted Answer

Number of moles of ethyl alcohol =(138/46)=3 Number of moles of water =(72/18)=4 XC2H5OH=(3/3+4) =(3/7) XH2O=(4/3+4) =(4/7) (XC2 H5 O H/XH2 O)=(3 / 7/4 / 7) =(3/4)

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

3 : 4

1 : 2

1 : 4

1 : 1

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

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