Chem 305 Lab Exercie \#A - Chemical Composition (Hydrates) CoCl2+6H2O CuSO45H2O CaCl22H2O CaSO42H2O MgSO47H2O Part I Procedure Part I Procedure In this part, you will quantitatively analyze a sample of copper(II) sulfate pentahydrate (CuSO45H2O) and determine experimentally its \%-hydration or % water. 1. Flame dry a crucible with lid. To do this, place the crucible in a clay triangle supported by a ring on a ring stand above a Bunsen burner. The burner top should be approximately 2 to 4cm from the bottom of the erucible. The tip of the inner blue cone flame should spread over the bottom of the crucible, when lit. Heat the crucible and lid until the bottom of the crucible glows a faint orange color. 2 Let cool and determine the mass of the crucible and its lid separately (this is important as the lids are easily broken!). Be careful to keep each lid and erucible together as a set if you dry more than one crucible and lid. 3. Place between 1-2 gram of your hydrate into the crucible and record the weight of the sample, crucible, and lid accurately to the milligram valuc. 4. Place the crucible with hydrate on the clay triangle. Since the crystals may pop and splatter as heated, the lid needs to be on the crucible to minimize any loss of sample. However, it is usually necessary to set the lid on the crucible slightly ajar so that the water of hydration can escape as steam. 4.3 Chem 305 Lab Exercise \$4-Chemical Composition (Hydrates) 5. Heat the sample gently with the Bunsen burner, periodically checking the color change of the sample by removing the heat and lifting the crucible top. Once you have achieved a consistent color for the sample, remove the heat. Note: A color change is only evident if the hydrate is colored to begin with. 6. Let the sample cool, and then weigh the crucible with the sample and lid. Repeat the heating, cooling, and weighing (at least a second time) until a stable weight has been reached (the difference between two successive weightings is