Calculate the mass of sodium sulphate required to prepare its 20 persent (mass percent) solution in 100g of water?

Question

Calculate the mass of sodium sulphate required to prepare its 20% (mass percent) solution in 100g of water?

Answer 1

Let the mass of sodium sulphate required be = x g 

The mass of solution would be = (x +100) g 

x g of solute in (x + 100) g of solution 

20% = ×/x+100 x100 

20 x + 2000= 100 x 

80 x = 2000 

x = 2000/ 80 

= 25 g