Purification and Distillation of Liquids

Purification of Water from Substances Dissolved in It. Assemble an apparatus as shown in Fig. 32. Fill cooler 2 with water. Feed the water upward through the cooler (why ). Prepare (draw out) 8-10 glass capillaries 10-12 mm long and seal them at one end. 

Pour 250 ml of hydrochloric acid into a 0.5-litre round-bottomed flask. Submerge the prepared glass capillaries in the flask containing the acid with their open ends downward. Close the flask with a stopper containing a dephlegmator and a thermometer. Heat the acid in the flask up to boiling. Cover the receiver with cotton wool or filter paper. Note the initial temperature at which the acid boils. How will the temperature at which the acid boils change as the liquid is distilled  

When the boiling point of the liquid becomes constant, change the receiver and distil 100 ml of the liquid into the new receiver. Measure the density of the liquids in the receiver and in the Wurtz flask. What is the hydrogen chloride percentage in them Define an azeotropic mixture. 

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