Question

The lead-acid storage battery is the oldest rechargeable battery in existence. It was invented in 1859 by French physician Gaston Plante and still retains application today, more than 150 years later. There are two reactions that take place during discharge of the lead-acid storage battery. In one step, sulfuric acid decomposes to form sulfur trioxide and water: H2SO4 (l) → SO3 (g) + H2O (l) ΔH=+113.kJ In another step, lead, lead(IV) oxide, and sulfur trioxide react to form lead(II) sulfate: Pb (s) + PbO2 (s) + 2SO3 (g) → 2PbSO4 (s) ΔH=−775.kJ Calculate the net change in enthalpy for the formation of one mole of lead(II) sulfate from lead, lead(IV) oxide, and sulfuric acid from these reactions. Round your answer to the nearest kJ .

Answer 1

Write the two reactions A, +113 kJ Divide the equation (2) by coefficient 2. АН Add equation (1) and (3) Pb (sPbO2(s) + SO, (gPbSO4(s) H,SO, (I) +-РЫ(s) + 2 PbO, (s) PbSO4 (s) + H,O(1) (4)

Calculate the change in enthalpy for the reaction (4) as follows: AH AX (113k)775kJ) 113 k -274.5 kJ -275 k change forthe formation of one mole of lead (Isulfate is