If in a lead storage battery the reaction at the cathode is:
PbO₂(s) + 4 H⁺(aq) + SO₄^2- (aq) + 2 e^- → PbSO₄(s) + 2 H₂O(l)
How many grams of lead sulfate are formed on one plate if 20.A average current occurs for 2.0 minutes? Assume 100% efficiency.

Question

Quizplus · Accepted Answer

The charge passed is 20 A * 120 s = 2400 C. The reaction involves 2 electrons, so 1 mole of PbSO4 requires 2 * 96485 C. Thus, moles of PbSO4 = 2400 C / (2 * 96485 C/mol) = 0.0124 mol. The molar mass of PbSO4 is 303.26 g/mol, so mass = 0.0124 mol * 303.26 g/mol = 3.8 g.

If in a Lead Storage Battery the Reaction at the Cathode