Final answer:
The molecular mass of the gas is 0.088 g/mol.
Step-by-step explanation:
The molecular mass of a gas can be calculated by using the ideal gas law and the given gas density. The ideal gas law equation is PV = nRT, where P is the pressure, V is the volume, n is the number of moles of gas, R is the ideal gas constant, and T is the temperature. Rearranging the equation to solve for n, we get n = (PV)/(RT). Given the density of the gas as 1.98 g/L, we can convert this to moles using the molar mass equation MM = (density)/(molar volume), where molar volume is 22.4 L/mol at STP. Plugging in the values, we get MM = (1.98 g/L)/(22.4 L/mol) = 0.088 g/mol. Therefore, the molecular mass of the gas is 0.088 g/mol.