Solubility of Sodium Chloride by xKzePR0

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									Solubility of Sodium Chloride
Introduction                       If you add Kool Aid crystals to water the crystals will
                                   dissolve. If you continue to add Kool Aid, you eventually
                                   reach a point where no more crystals will dissolve. The
                                   solution is now said to be saturated. The amount of solute
                                   present in a saturated solution is the solubility of that
                                   solute.

                                   The solubility of a solute in water depends on temperature
                                   of the water e.g. more Jello will dissolver in hot water than
                                   in cold. The table below gives the solubility of sodium
                                   chloride in water at different temperatures.


                                                  Solubility of Sodium
                                                   Chloride in Water
                                           Temperature              Solubility
                                              ( ºC)                (g/100 mL)
                                                0                      31.6
                                                 70                    33.0
                                                100                    33.6



Purpose                            To determine the solubility of sodium chloride in water at
                                   room temperature.


Design                             A 10.00 mL sample of saturated sodium chloride solution
                                   will be evaporated to dryness and the mass of sodium
                                   chloride present in that solution will be determined.


Prediction                         Use the data above to plot a graph of solubility vs
                                   temperature for sodium chloride.



Materials                          10 mL pipet                   evaporating basin
                                   Hot plate                     balance
                                   100 mL beaker                 saturated NaCl(aq)
                                   thermometer




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 Procedure                          1. Pour approximately 40 mL of saturated sodium chloride
                                       solution into a 100 mL beaker.

                                    2. Measure and record the temperature of the solution to the
                                       nearest 0.1 ºC.

                                    3. Determine and record the mass of an evaporating basin.

                                    4. Pipet a 10.00 mL sample of saturated solution into the
                                       evaporating basin.

                                    5. Place the basin on the hotplate and heat the solution until
                                       the water has completely evaporated.

                                    6. Allow the basin to cool and then determine the mass of
                                       the basin and its contents.

                                    7. Repeat steps 5 and 6 until the mass is constant.


 Evidence                           Record your data below:

                                    Volume of saturated solution                   10.00 mL

                                    Temperature of the saturated solution                    ºC

                                    Mass of the evaporating basin                            g

                                    Final mass of the basin and contents                     g


Analysis                            1. Use your graph to predict the solubility of sodium
                                       chloride at room temperature.




                                    2. Use your data to calculate the solubility of sodium
                                       chloride, at room temperature, in g/100mL.




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Conclusion                         State the solubility of sodium chloride at room temperature
                                   from your data. Compare your calculated answer with the
                                   predicted by determining a percentage error.




Evaluation                         If your percentage error exceeded 5%, suggest reasons to
                                   account for the error.




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