Conc. aq. sulphuric acid is 98% H2SO4 by mass and has a density of 1.84g cm-3. What volume of the concentrated acid is required to make 5 litres of 0.5M H2SO4?

Question

I've got an assignment of 87 questions this being the 54th. I tried solving but ended with 133152.1739ml as the final value. (I'm sorry Im horrible at chemistry n i've come here seeking for some help as im unable to approach any tutor for the time being.) thank u.

Answer 1

To make 0.5 M H₂SO₄, you need 0.5 moles/liter.  To make 5 liters, you need 0.5 moles/L x 5 L = 2.5 moles of H₂SO₄.

Molar mass of H₂SO₄ is 98 g/mole.  2.5 moles x 98 g/mole = 245 g of H₂SO₄ needed.

1.84 g/ml (x ml) = 245 g and x = 133.15 ml needed, if it were pure, 100% H₂SO₄.

Correcting for the 98% purity, you need 133.15/0.98 = 135.87 ml of the 98% H₂SO₄.  

You can adjust this to the number of sig.figs. required.  It should be to 1 sig.fig. based on the 0.5 M and the 5 liters, but I'll leave that to you.