What is the mass of lead?

Question

When 2.00 mol of PbSO₄ forms in the following reaction, 768 kJ are released.

Pb(s) + PbO₂(s) + 2SO₃(g) → 2PbSO₄(s)

What mass of lead, Pb(s), is used up when 2100 kJ of energy are released?

Answer 1

Pb(s) + PbO₂(s) + 2SO₃(g) → 2PbSO₄(s) ... balanced equation

From the balanced equation we see that 1 mol of Pb reacts to produce 2 mol PbSO4 and 768 kJ of energy are released. Using this information plus the atomic mass of Pb (207 g/mol) and dimensional analysis, we an easily answer this question.

2100 kJ x 1 mol Pb/768 kJ x 207 g Pb/mol = 566 g Pb