Calculate the molar mass of a gas that has a density of 1.963 g/L at STP.

Question

Quizplus · Accepted Answer

At STP, the temperature and pressure are 273 K and 1 atm, respectively. The ideal gas law, PV = nRT, can be rearranged to solve for the molar mass (M).

M = (mRT/PV)

Since the gas has a density of 1.963 g/L at STP, we can convert this to mass per unit volume:

m/V = density = 1.963 g/L

Substituting this into the expression for molar mass yields:

M = (mRT/PV) = [(1.963 g/L)(0.08206 L atm/mol K)(273 K)] / (1 atm) = 44.00 g/mol

Therefore, the correct answer is C.

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