The molecular weight of a gas that has a density of 7.10 g/L at 25.0 °C and 1.00 atm pressure is ________ g/mol. A)174 B)14.6 C)28.0 D)5.75 × 10^-3 E)6.85 × 10^-2

Question

Quizplus · Accepted Answer

The molecular weight of a gas can be calculated using the ideal gas law equation rearranged in terms of molar mass (M): M = (dRT)/(P), where d is the density of the gas (7.10 g/L), R is the ideal gas constant (0.0821 L·atm/(K·mol)), T is the temperature in Kelvin (25.0 °C + 273.15 = 298.15 K), and P is the pressure (1.00 atm). Plugging in the values gives M = (7.10 g/L * 0.0821 L·atm/(K·mol) * 298.15 K) / 1.00 atm = 174 g/mol.

The Molecular Weight of a Gas That Has a Density