Question

A solution is made by dissolving 9.74 g of sodium sulfate in water to a final volume of 165 mL of solution. What is the weight/weight % or percent by mass of the solute?

Answer 1

Answer: The weight/weight % or percent by mass of the solute is 5.41 %.

Explanation:

Mass of the sodium sulfate,w = 9.74 g

Volume of the water = 165 mL

Density of the water = 1 g/mL

$Density=1 g/mL=\frac{\text{Mass of water}}{\text{Volume of water}}$

Mass of the water =$1 g/mL\times 165 mL=165 g$

Mass of the solution, W:

Mass of solute + Mass of solvent =9.47 g + 165 g=174.47 g

$w/w\%=\frac{w\times 100}{W}=\frac{9.45 g\times 100}{174.47 g}=5.41 \%$

The weight/weight % or percent by mass of the solute is 5.41 %.