Answer:The mass of a single water molecule can be calculated using its molecular formula, H2O. The molecular weight of water is 18.015 g/mol.If we have 3.01 x 10^24 water molecules, the total mass can be calculated as follows:Mass = Number of water molecules * Molecular weight of waterMass = 3.01 x 10^24 * 18.015 g/molMass = 5.45 x 10^25 gSo, the mass of 3.01 x 10^24 water molecules is approximately 5.45 x 10^25 grams.