Question

what volume of 96 % H2 S o4 solution is required to prepare 4 litre of 3 molar H2 S o4 solution

Answer 1

1000 mL of 96% H2SO4 contains 0.96 * 1.84 g/mL * 1000 mL = 1766.4 g.

1766.4 g / 98.079 g/mol = 18.01 moles so 1000 mL contains 18 moles.

4 L * 3.0 mol/L = 12 moles. Now we do the ratio:

12 / 18 * 1000 mL = 666.66 = 667 mL 96% sol'n needed.