Question

Calculate the mass of sodium sulphate required to prepare a 20% solution in 100 g of water?

Answer 1

Given:
Concentration (m/m) % of sodium sulphate solution = 20%
Mass of the solvent = 100 g

Let the mass of solute (sodium sulphate) = x g
$20=\frac{x}{x+100}\times 100$

$80x=2000$
$x=25$
Mass of sodium sulphate = 25 g