Question

A bottle of sulphuric acid (d=1.787 g/ml) is labelled 86% by mass. What is the molarity of the solution? What volume of the acid is required to make 1L of 0.2M H2SO4?

Answer 1

A bottle of commercial H2SO4
Density = 1.787g/ml
% weight = 86%

Part -1
Moles of H2SO4 in 100.0 g of 86 % solution :

= 86.6 g of this solution is H2SO4
= 86.6 / 98 g/mol
= 0.89 mol

Volume of 100.0 g of solution

Density = mass / volume
1.787 g/mL = 100.0 g / Volume
Volume = 55.95 mL

Molarity
= 0.89 mol / [(55.95 /1000 L)]
= 15.9 M

Part- 2

M1V1 = M2V2
0.2×1000 = 15.9 ×Volume of Acid

Volume of Acid = (0.2 /15.9)×1000 = 12.57 mL