Question

A liquid mixture contains 1 kg of water, 1.9 lb of ethanol, and 4.6 lb of methyl acetate. What is the weight fraction of ethanol in this mixture? Report your answer to the nearest hundredths place.

Answer 1

Answer: The weight fraction of ethanol in the mixture is

Explanation:

We are given:

Mass of water = 1 kg = 2.205 lb   (Conversion factor:  1 kg = 2.205 lb)

Mass of ethanol = 1.9 lb

Mass of ethyl acetate = 4.6 lb

Mass of mixture = [2.205 + 1.9 + 4.6] = 8.705 lb

To calculate the percentage composition of ethanol in mixture, we use the equation:

$\%\text{ composition of ethanol}=\frac{\text{Mass of ethanol}}{\text{Mass of mixture}}\times 100$

Mass of mixture = 8.705 lb

Mass of ethanol = 1.9 lb

Putting values in above equation, we get:

$\%\text{ composition of ethanol}=\frac{1.9lb}{8.705lb}\times 100=21.8\%$

Hence, the weight fraction of ethanol in the mixture is 21.8 %