Final answer:
The mass of a mole of gas X with a density of 1.00 gram per liter at STP is 22.4 grams, which is option D.
Step-by-step explanation:
If the density of gas X at STP is 1.00 gram per liter, the mass of a mole of gas X is determined using the concept that 1 mole of a gas at STP occupies 22.4 liters. To calculate the molar mass of gas X, we use the formula: Molar Mass (MM) = density (p) × molar volume (Vm). Given that the density (p) is 1.00 g/L and the molar volume (Vm) at STP is 22.4 L/mol, the calculation is as follows:
MM = 1.00 g/L × 22.4 L/mol
MM = 22.4 g/mol
Therefore, the mass of a mole of gas X is 22.4 grams, which corresponds to option D.