Question

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

• A. 25 g
• B. 30 g
• C. 50 g
• D. 60 g

Answer 1

The correct option is A 25 g

Let the mass of sodium sulphate required be $=xg$

The mass of solution $=(x+100)g$

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

20% $=\frac{x}{x+100}\times 100$

$20x+2000=100x$

$80x=2000$

$x=\frac{2000}{80}=25g$