Question

What mass of sodium sulphate is needed to make 275g of its 1.5 percent by weight aqueous solution?

Answer 1

Explanation:

1 molecule of Na2SO4 contains 2 atoms of Na, 1 atom of sulfur and 4 atoms of oxygen. 1 mole of Na2SO4 contains 7 moles of atoms. Molecular weight of Na2SO4 is (2*23)+(1*32)+(4*16) = 46+32+64 = 142 grams. 142 grams of Na2SO4 contains 7 moles of atoms.

Answer 2

Answer:

4.13g is the required answer.