Final answer:
To determine the mass of a sample of water containing 3.55x10^22 molecules of H2O, we need to use the conversion factor of the molar mass of water.
Step-by-step explanation:
To determine the mass of a sample of water containing 3.55x1022 molecules of H2O, we need to use the conversion factor of the molar mass of water.
The molar mass of H2O is 18.015 g/mol. To convert from mass to moles, we take the reciprocal of 1 mol/18.015 g. Multiplying the number of molecules by this conversion factor gives us the mass of the sample.
Therefore, the mass of the sample of water is 3.55x1022 molecules x 1 mol/18.015 g = 1.97x1020 g.