Solutions Question 146
Question: A mixture has 18g water and 414g ethanol. The mole fraction of water in mixture is (assume ideal behaviour of the mixture) [MP PMT 2000]
Options:
A) 0.1
B) 0.4
C) 0.7
D) 0.9
Show Answer
Answer:
Correct Answer: A
Solution:
Molecular weight of $ C_2H_5OH=24+5+16+1=46 $
Molecular mass of $ H_2O=18 $
414g of $ C_2H_5OH $ has $ \frac{414}{46}=9 $ mole
18g of $ H_2O $ has $ =\frac{18}{18}=1 $ mole
Mole fraction of water $ =\frac{n_1}{n_1+n_2}=\frac{1}{1+9} $
$ =\frac{1}{10}=0.1 $
