Question

A solution of sulfuric acid contains 35.2% by mass of H2SO4 and has a density of 1.27 g/mL. What is the molarity of H2SO4 in this solution?

Answer 1

[H₂SO₄] = 4.56 M

Step-by-step explanation:

35.2 % by mass of H₂SO₄ means that in 100 g of solution, we have 35.2 grams of solute.

We convert the mass of solute to moles.

35.2 g / 98 g/mol = 0.359 moles

These moles are contained in 100 g of solution, so we use density to determine the volume.

1.27 g/mL = 100 g / volume

Volume = 100 g / 1.27 g/mL = 78.74 mL

Molarity is mmol /mL (either we can say, moles in 1L of solution).

We convert the moles to mmoles → 0.359 mol . 1000 = 359 mmoles

M = 359 mmoles/74.74 mL = 4.56 M