A 25-L container holds ideal hydrogen (H₂) gas at a gauge pressure of 0.25 atm and a temperature of 0°C. What mass of hydrogen gas is in this container? The ATOMIC mass of hydrogen is 1.0 g/mol, the ideal gas constant is R = 8.314 J/mol•K = 0.0821 L ∙ atm/mol ∙ K, and 1.00 atm = 101 kPa. A) 1.4 g B) 2.8 g C) 4.2 g D) 5.6 g E) 6.3 g

Question

Quizplus · Accepted Answer

First, convert the gauge pressure to absolute pressure: 0.25 atm + 1 atm = 1.25 atm. Use the ideal gas law: PV = nRT. Solve for n (moles): n = PV/RT = (1.25 atm)(25 L) / (0.0821 L∙atm/mol∙K)(273 K) ≈ 1.4 mol. The molar mass of H₂ is 2 g/mol, so the mass is 1.4 mol × 2 g/mol = 2.8 g.

A 25-L Container Holds Ideal Hydrogen (H2) Gas at a Gauge

A 25-L Container Holds Ideal Hydrogen (H₂) Gas at a Gauge