A sealed reaction vessel volume is 0.5 dm³ contains argon gas at 1 atm and 21 °C. Assuming that argon behaves ideally under these conditions calculate the mass of Ar in the reaction vessel.

Question

Quizplus · Accepted Answer

Using the ideal gas law, PV = nRT, where P is pressure, V is volume, n is the number of moles, R is the gas constant, and T is temperature:

n = (PV)/(RT)

n = (1 atm * 0.5 dm3)/(0.0821 L atm/mol K * 294 K)

n = 0.0212 mol

The mass of Ar in the reaction vessel can be calculated using the molar mass of Ar:

mass = n * molar mass

mass = 0.0212 mol * 39.95 g/mol

mass = 0.847 g

Therefore, the correct choice is C (0.83 g).

A Sealed Reaction Vessel Volume Is 0