So oxygen is 16 grams/mol plus two times because we have a substitute to 1 gram per mole, gives us 18 grams/mol. So the molecular weight of water is 18 grams/mol. Finally, we take this guy divided by this guy and we get 5.56
moles of water. That's how you find moles. The second step is the same exact step, except it's for ethylene glycol. Now we have to look up the density of ethylene glycol and the molecular formula for ethylene glycol.