A 1.50 L flask contains 0.0600 mol of an ideal gas at a pressure of 1.25 atm. What is the temperature of the gas in degrees Celsius? (R = 0.0821 L·atm·mol⁻¹·K⁻¹)

Correct answer

A. 108 °C

Principle or equation

The ideal gas equation is PV = nRT. Solve for T in kelvin, then convert to Celsius by subtracting 273.15.

Why this answer is correct

Using PV = nRT, T = PV / (nR) = (1.25 atm × 1.50 L) / (0.0600 mol × 0.0821 L·atm·mol⁻¹·K⁻¹) = 1.875 / 0.004926 = 380.6 K. Convert to Celsius: 380.6 − 273.15 = 107.5 °C, which rounds to 108 °C.

Example

For 0.100 mol of gas at 1.00 atm and 2.00 L, T = (1.00 × 2.00) / (0.100 × 0.0821) = 243.6 K = −29.5 °C.