A lead storage battery consists of a lead anode and a grid of lead packed with lead dioxide as the cathode. The electrolyte taken is 39% H₂SO₄ by mass having a density of 1.294 g mL^-1. The battery holds 3.5 L of the acid. During the discharge of the battery, the density of H₂SO₄ falls from 1.294 g mL^-1 to 1.139 g mL^-1 which is 20% by H₂SO₄ mass.

What is the molarity of the solution after the discharge?

2.32

The correct answer is option 3. 2.32.

\(\text{Moles of }H_2SO_4\text{ present in the solution after the discharge = }\frac{797.3}{98}\text{ = 8.136}\)

∴ \(\text{Molarity of the solution = }\frac{8.316\text{ mol}}{3.5\text{ L}}\text{ = 2.32}\)