Question

Calculate the mass of sodium sulphate required to prepare 40%(mass per cent ) solution in 250 g of water

Answer 1

Answer:

500/3

Explanation:

hey, now see...for this question the knowledge of atomic masses of constituents is not required

"mass of solute/mass of solution*100= Mass percent"

here; mass %= 40%

Let mass of solute be x

Mass of solution= 250+x

substituting the values:

(x/250+x)*100= 40

x= (40/100)* (250+x)

x= [(2/5)(250)]+ [(2/5)(x)]

x- 2x/5 = 100

3x/5= 100

x= 500/3

Hence the mass of sodium sulphate required is 500/3 grams.