Question

A solution contains $27\%$ water, $36.8\%$ ethanol and $36.2\%$ ethanoic acid solution by mass. Calculate the mole fraction of each component in the same order.

• A. 0.23,0.5,0.26
• B. 0.5,0.23,0.26
• C. 0.26, 0.23, 0.5
• D. 0.5,0.26,0.23

Answer 1

The correct option is D 0.5,0.26,0.23

Consider $100$ g of solution, it contains $27$ g water, $36.8$ g ethanol and $42$ g of ethanoic acid.
Moles of water = $\frac{27}{18}=1.5$
Moles of ethanol =$\frac{36.8}{46}=0.8$
Moles of ethanoic acid $=\frac{42}{60}=0.7$
Total number of moles $1.5+0.8+0.7=3$
Mole fraction of water $=\frac{1.5}{3}=0.5$
Mole fraction of ethanol $=\frac{0.8}{3}=0.26$
Mole fraction of ethanoic acid $=\frac{0.7}{3}=0.23$