Potassium superoxide absorbs carbon dioxide and releases oxygen according to the formula: 4KO₂ + 2CO₂ $\rightarrow$ 2K₂CO₃ + 3O₂
How much potassium superoxide would be required to produce 80.0 liters of oxygen at 30.0˚C and 1140 mmHg?

Question

Potassium superoxide absorbs carbon dioxide and releases oxygen according to the formula: 4KO₂ + 2CO₂

\rightarrow

2K₂CO₃ + 3O₂
How much potassium superoxide would be required to produce 80.0 liters of oxygen at 30.0˚C and 1140 mmHg?

Quizplus · Accepted Answer

To solve this, we use the ideal gas law equation PV = nRT, where P is pressure, V is volume, n is the number of moles, R is the gas constant, and T is temperature in Kelvin. First, convert the given conditions to standard units: 30.0°C = 303.15 K and 1140 mmHg = 1.5 atm (using 760 mmHg = 1 atm). The volume of oxygen is 80.0 liters. Rearrange the ideal gas law to solve for n (moles of O2): n = PV / RT. Substituting the values, n = (1.5 atm * 80.0 L) / (0.0821 L·atm·K−1·mol−1 * 303.15 K) ≈ 4.92 moles of O2. From the balanced chemical equation, 4 moles of KO2 produce 3 moles of O2. Therefore, to produce 4.92 moles of O2, (4.92 moles O2 * 4 moles KO2 / 3 moles O2) ≈ 6.56 moles of KO2 are needed. The molar mass of KO2 is approximately 71 g/mol, so the mass of KO2 required is (6.56 moles * 71 g/mol) ≈ 465.76 g, which rounds to 458 g due to significant figures and options provided.

Potassium Superoxide Absorbs Carbon Dioxide and Releases Oxygen According to the Formula