If we look at the structure of water, we see that one mole of water consists of two moles of hydrogen atoms and one mole of oxygen atoms. Therefore, one mole of hydrogen equals 1 g/mol, whereas one mole of oxygen equals 16 g/mol. As a result, we have this equation below: [latex]Water = (2 \ imes 1) + (1 \ imes 16) = 18 [/latex] g/mol More precisely, it's 18.01528 g/mol.