Understanding Galena Extraction and Lead Oxide Formation Process

Understanding the Galena Extraction Process

Galena is the ore from which elemental lead is extracted. The extraction process involves heating Galena in air to form Lead(II) Oxide according to the reaction: 2PbS(s) + 3O2(g) → 2PbO(s) + 2SO2(g) ΔH = –827.4 kJ.

When 975 kJ of heat are liberated, the process converts 2.357 moles of Galena to Lead Oxide. This is determined by stoichiometric calculations, considering the molar mass of Galena. Since the molar mass of Galena (PbS) is 239.3 g/mol, the mass of Galena can be calculated as follows:

1. Find the heat released per mole of Galena: 827.4 kJ / 2 moles = 413.7 kJ/mol

2. Calculate the moles of Galena corresponding to 975 kJ: 975 kJ / 413.7 kJ/mol = 2.357 moles

3. Convert moles of Galena to mass: 2.357 moles * 239.3 g/mol = 563.8 grams

Therefore, when 975 kJ of heat are liberated in the process of converting Galena to Lead Oxide, the mass of Galena converted is 563.8 grams based on the stoichiometry of the reaction.