The thermal decomposition of potassium chlorate can be used to produce oxygen in the laboratory. 2KClO₃ (s) → 2KCl (s) + 3O₂ (g)
What volume (L) of O₂ gas at 25 °C and 1.00 atm pressure is produced by the decomposition of 7.5 g of KClO₃ (s) ?

Question

Quizplus · Accepted Answer

First, calculate the moles of KClO3: Molar mass of KClO3 = 122.55 g/mol. Moles of KClO3 = 7.5 g / 122.55 g/mol = 0.0612 mol. From the balanced equation, 2 moles of KClO3 produce 3 moles of O2. Therefore, 0.0612 mol of KClO3 produces (3/2) * 0.0612 = 0.0918 mol of O2. Use the ideal gas law to find the volume: V = nRT/P. R = 0.0821 L·atm/mol·K, T = 298 K, P = 1 atm. V = 0.0918 mol * 0.0821 L·atm/mol·K * 298 K / 1 atm = 2.3 L.

The Thermal Decomposition of Potassium Chlorate Can Be Used to Produce