Measure The Percent Of Water

1008 WordsFeb 15, 20165 Pages
Purpose The purpose of this experiment is to measure the percent of water in a series of crystalline compounds called hydrates. Introduction Percent composition is “the relative amount of the elements in a compound, or the percent by mass of each element in the compound” (Wilbraham, Staley, Matta, Waterman). It can be calculated by two ways, and it can also be used as a conversion factor. In this lab experiment, the percent composition will be determined to figure out how much water is in three hydrates, “a chemical compound that has water in its composition (as water of crystallization)” (Dictionary of Earth Science, Revised Edition). This being said, the bonds that hold the water molecules in the hydrates are not strong, due to the polarity of water and the ionic nature of salt, so water can be easily lost. Heating up a hydrate can cause the water to be driven away and leave anhydrous salt behind, and because the water’s mass is a part of the hydrate’s mass, the mass of the hydrate after heating it up will change. Hypothesis If the hydrates are heated, then the molar mass of the compound will become lower because the moisture is being driven from them. Materials 1. 3 medium-sized test tubes 2. Balance 3. Spatula 4. Hydrated compounds of copper (II) sulfate, calcium chloride, and sodium sulfate 5. Test tube holder 6. Gas burner Procedure 1. Label each of the 3 test tubes with the name of a compound (copper (II) sulfate, calcium chloride, and sodium sulfate), and
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