Question: how many moles are in 25 grams of water show work?
Answer: Hydrogen has an atomic weight of 1; and oxygen has an atomic weight of 16 (check the periodic table for the atomic weights). So, one mole of water has a mass of 16 +1+1 = 18 grams. So, if one mole has a mass of 18 grams, 25 grams would have a mass of 25 grams/ 18 grams per mole or 1.39 moles.