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Experiment 1. Refining Sodium Chloride. Purposes. 1. To master the usage of glassware washing , alcohol burner and platform balance. 2. Practice the basic operation of dissolving, filtrating, evaporating, concentrating and drying. 3. To learn the general theories and methods of
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Experiment 1 Refining Sodium Chloride
Purposes 1. To master the usage of glassware washing, alcohol burner and platform balance. 2. Practice the basic operation of dissolving, filtrating, evaporating, concentrating and drying. 3. To learn the general theories and methods of refining sodium chloride.
Principles • Crude salt usually contains soluble ions, such as Ca2+、 Mg2+、SO42-、K+ and other insoluble impurities. The insoluble material can be removed by filtrating the solution of crude salt and the soluble ones can be eliminated by adding the proper reagents (for example, BaCl2, Na2CO3, HCl, etc.) to the solution of crude in which the precipitate can form.
Procedure • 1.Refining sodium chloride 15ml H2O BaCl 2 Weigh out 4g crude salt dissolving △ △ Adding NaOH,Na2CO3 solution (evaporating dish) K+、OH-、CO32- filtrating concentrating pH=4-6 NaCl crystal HCl drying
2.Test the purity of the purified salt • test the SO42- BaCl 2 solution • test the Ca2+ ion (NH4)2C2O4 solution • test the Mg2+ ion magnesium agent
yield of product (%)= Recording and handling data 1. Refining the sodium chloride weight of crude salt m1 = g, weight of purified salt m2 = g