Potassium chlorate decomposes upon heating as follows:
2KClO₃(s) → 2KCl(s) + 3O₂(g)
A 2.72-g sample of KClO₃ decomposes, and the oxygen at 23.4°C and 0.935 atm is collected. What volume of oxygen gas will be collected, assuming 100% yield?

Question

Quizplus · Accepted Answer

To find the volume of oxygen gas collected, use the ideal gas law: PV = nRT. First, calculate moles of KClO3: 2.72 g / 122.55 g/mol = 0.0222 mol. From the balanced equation, 2 mol KClO3 produces 3 mol O2, so 0.0222 mol KClO3 produces 0.0333 mol O2. Convert temperature to Kelvin: 23.4°C = 296.55 K. Use R = 0.0821 L·atm/mol·K. Solve for V: V = nRT/P = (0.0333 mol)(0.0821 L·atm/mol·K)(296.55 K) / 0.935 atm = 0.866 L = 866 mL.

Potassium Chlorate Decomposes Upon Heating as Follows