A 0.50 L cylinder contains 0.820 grams of an unknown gas. The pressure inside the cylinder is 2.50 atmospheres at 25.0 °C. What is the identity of the unknown gas?

Question

Quizplus · Accepted Answer

Using the ideal gas law, PV = nRT, we can calculate the molar mass of the gas. First, convert the temperature to Kelvin (25°C = 298 K). The number of moles (n) is calculated as n = PV/RT. Using R = 0.0821 L·atm/mol·K, n = (2.50 atm * 0.50 L) / (0.0821 L·atm/mol·K * 298 K) = 0.051 moles. The molar mass is then mass/n = 0.820 g / 0.051 moles ≈ 16.0 g/mol, which corresponds to CH₄.

A 050 L Cylinder Contains 0