Hydrate Analysis
Hydrates Analysis
NAME:_____________________________________ PERIOD:_________
Prelab
1. A 6.00g sample of calcium sulfate hydrate (CaSO4.x H2O) is heated until all the water is driven off. The anhydrous compound has a mass of 4.77 g. Calculate the value of x in the formula.
2. For the data in problem number 1 above, what is the mass percent water in the hydrate?
3. Calculate the number of grams of water that could be obtained by heating 2.00 g of sodium sulfate decahydrate (Na2SO4.10 H2O).
Hydrates Analysis
Objective: The formula for an unknown hydrate is quantitatively determined by heating the unknown hydrate to constant mass and calculating the ratio of the moles of water to the moles of anhydrous material. Observations will be made of any color changes during heating and re-hydration of the compound as well as heat effects during the re-hydration.
A hydrate is a compound that is associated with a definite number of water molecules. The water is present as individual water molecules and usually no chemical bonds are involved in holding the ions of the compound and the water molecules together. The forces of attraction are electrostatic forces resulting from the charged nature of the anhydrous ionic compound and the polar water molecules. Particle size and space limitations dictate the number of water molecules an ionic compound will accommodate and well as the conditions under which the hydrate is formed. Many ionic compounds form multiple hydrates and to remove all of the bound water for some of these can be difficult in ordinary laboratory conditions and time constraints. Hydrates are classified as hygroscopic, deliquescent, and effluorescent. These labels specify the properties associated with the ionic compound to which the water is bound. The type of hydrate most suitable for a quantitative hydrate formula determination is the hygroscopic hydrate, which absorbs a definite number of
NAME:_____________________________________ PERIOD:_________
Prelab
1. A 6.00g sample of calcium sulfate hydrate (CaSO4.x H2O) is heated until all the water is driven off. The anhydrous compound has a mass of 4.77 g. Calculate the value of x in the formula.
2. For the data in problem number 1 above, what is the mass percent water in the hydrate?
3. Calculate the number of grams of water that could be obtained by heating 2.00 g of sodium sulfate decahydrate (Na2SO4.10 H2O).
Hydrates Analysis
Objective: The formula for an unknown hydrate is quantitatively determined by heating the unknown hydrate to constant mass and calculating the ratio of the moles of water to the moles of anhydrous material. Observations will be made of any color changes during heating and re-hydration of the compound as well as heat effects during the re-hydration.
A hydrate is a compound that is associated with a definite number of water molecules. The water is present as individual water molecules and usually no chemical bonds are involved in holding the ions of the compound and the water molecules together. The forces of attraction are electrostatic forces resulting from the charged nature of the anhydrous ionic compound and the polar water molecules. Particle size and space limitations dictate the number of water molecules an ionic compound will accommodate and well as the conditions under which the hydrate is formed. Many ionic compounds form multiple hydrates and to remove all of the bound water for some of these can be difficult in ordinary laboratory conditions and time constraints. Hydrates are classified as hygroscopic, deliquescent, and effluorescent. These labels specify the properties associated with the ionic compound to which the water is bound. The type of hydrate most suitable for a quantitative hydrate formula determination is the hygroscopic hydrate, which absorbs a definite number of