Final answer:
The mass of 9.00 moles of water is 162.0 grams, calculated by multiplying the number of moles by the molar mass of water (18.0 g/mol).
Step-by-step explanation:
To calculate the mass of 9.00 moles of water, you use the molar mass of water as a conversion factor. The calculation is straightforward:
Mass = moles × molar mass
Mass = 9.00 moles × 18.0 g/mol
Mass = 162.0 grams
Thereby, the mass of 9.00 moles of water is 162.0 grams.
The molar mass of a compound such as water is calculated by summing the atomic masses of all the atoms in its molecular formula. In the case of water (H₂O), this is the sum of twice the atomic mass of hydrogen plus the atomic mass of oxygen. Since hydrogen has an approximate atomic mass of 1 g/mol and oxygen has an atomic mass of 16 g/mol, one mole of water weighs approximately 18 g (16 g + 1 g + 1 g).