Solubility Equilibrium of Sodium Chloride

Problem Solubility equilibrium of a salt is not limited to the concentrations of the ions that deliver the pure salt solution. If, for example, a large amount of chloride ions are added to the saturated sodium chloride solution, then the equilibrium deviates in such a way that solid sodium chloride is formed and precipitates (Le Chatelier s principle of getting rid of the stress ). This way, the position of equilibrium is altered however, the product of concentrations of sodium ions and chloride ions remain constant solubility product. 

Material Test tube, pipette saturated sodium chloride solution, concentrated hydrochloric acid. 

Procedure Fill a test tube to half of its volume with saturated sodium chloride solution and carefully add several drops of hydrochloric acid. Repeat the additions of hydrochloric acid. 

Observation Immediately after the addition of concentrated hydrochloric acid, white crystals of salt are formed and deposited on the bottom of the test tube sodium chloride. 

Material Small beakers, equipment for measuring electrical conductivity and tester, balances, graduated cylinder calcium sulfate, magnesium sulfate. 

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