INORGANIC_CHEMISTRY_EXPERIMENTTION.pdf (original) (raw)

Subject: Pure Sodium Chloride from Common Salt materials required dropping funnel, round buttom flask, Erlenmeyer flask, funnel, beaker, glass tube, rubber tube common salt(NaCl), BaCl 2 , (NH 4 ) 2 C 2 O 4 , dye (paranitrobenzen-azo-resorcinol), NaOH,c-H 2 SO 4 ,c-HCl procedure Dissolve 50 grams of common salt in 150 ml of hot water. Cool, filter, and test small portions of the solution qualitatively for sulfate, calcium, and magnesium. To test for sulfate, add barium chloride and dilute hydrochloric acid; for calcium,add ammonium oxalate; for magnesium, add a few drops of a dilute solution of the dye paranitrobenzene-azo-resorcinol followed by 2N sodium hydroxide.In the last test, magnesium gives magnesium hydroxide colored blue by the dye; the blue is distinct from the purple color the dye itself gives with sodium hydroxide. Fig.1. Pure sodium chloride from common salt Place the remaining solution in an Erlenmeyer flask and pass over it a slow stream of hydrogen chloride gas, generated by dropping concentrated sulfuric acid into concentrated hydrochloric acid. To prevent the hydrogen chloride gas from passing out into the room, it is absorbed in sodium hydroxide solution by use of the funnel arrangement shown in Fig.1. Note: (a) The gas is passed over the salt solution and not through it. (b) The funnel dips only a millimeter or so below the surface of the sodium hydroxide. The reasons for these arrangements should be clear.