i might get confusing cause i dont understand this very much but here is the copy of my lab i need help with #1 & 6 of the POST-ALAYSIS here is the word doc. of my lab http://courses.digitaldapp.org/documents/Inquiry Lab - Experiment 03 - Composition of a Hydrate.doc btw. 5 grams of copper II sulfate was used when it became an anyhride it had a mass of 0.15g i know i made a mistake somewhere in my lab and i was wondering if you tell where my mistake is and what i should do. i would highly appreciate it. so i know... CuSO4 . 5H2O molar weight is 249.69g by itself is CuSO4 = 159.61g 5H2O= 90.81 so i took the mass of the water/total mass of hydrate x100= 36% of H2O removed in anhydrous copper (II) sulfate. am i correct? this is where i got confused... -determine the # of moles of water present in each mole of hydrous copper (II) sulfate. so what i did was: 5H2O H10= 11%=11/1.0079=10.91=2 O5=88%=88/15.9994=5.5=1 is this the correct Empirical formula? 2H10O5 & can be simplified to 2H2O so now what do i use to find the amount of moles of water present?