Question: how many moles are in 5 grams of h2o?
Answer: Well 1 mole of water is 2 moles of hydrogen + 1 mole of oxygen - that is; 1.008 x 2, + 16, which is 18.016 grams. Multiply that by the number of moles - 5, so that's 90.08 grams, or about 90mL. There are 90 grams in 5 moles of water.