Question

A solution is 25% water, 25% ethanol, and 50% acetic acid by mass. Calculate the mole fraction of each component

Answer 1

Step 1: Calculating the masses

Let the total mass of the solution be 100g

$\therefore$mass of the water= 25g

$\therefore$mass of the ethanol= 25g

$\therefore$mass of the Acetic acid= 50g

Step 2: Calculating the moles

The number of moles of water is:$\frac{25}{18}=1.4$

The number of moles of ethanol is:$\frac{25}{46}=0.54$

The number of moles of acetic acid is:$\frac{50}{60}=0.8$
$\therefore$Total number of moles $=(1.4+0.54+0.8)=2.74$

Step 3: Calculating the mole fraction

The mole fraction of water is $\frac{1.4}{2.74}=0.51$

The mole fraction of ethanol is $\frac{0.54}{2.74}=0.197$

The mole fraction of acetic acid is $\frac{0.8}{2.74}=0.291$

Therefore, the mole fraction of water, ethanol, and acetic acid are $0.51,0.197,0.291$ respectively.