How can you tell how much water is inside a hydrated crystal?
A hydrated crystal is a crystal that has water in it but is not a liquid, ok so supose you have X CaSO4 H20 (Calcium Sulfate) you take a sample and mass it (3 g) then you place it into a crucible and evaporate the water, mass whats left – crucible mass = (1 g) that is how much crystal was present in the orig 3 g sample 3 – 1 = 2g << mass of H20 evaporated\ then the Mole ratio, is how much H20 is in 1 mole of the Crystal, so you take the two masses and find the moles of each lets assum the molar mass of CaSO4 is 40 and H20 is 18 Mole CaSO4 : 1g / 40 Mole H20: 2g / 18 Mole ratio: .025/.111= . 225 Ideally it would be a whole number but it was just an example. EDIT: mole ratio: H20/Crystal therefore .111/.025 = 4.44 thats better..
