CHAPTER 17 – COMPOUNDS, MIXTURES AND SEPARATION OF MIXTURES Evaporation
Evaporation is used to separate a solid that does dissolve in liquid from a liquid. The liquid is evaporated, and the solid is left behind. An example of a mixture that can be separated by evaporation is salt and water.
Distillation is used to separate a solid that does dissolve in liquid from a liquid when you want to keep the liquid or to separate two miscible liquids (liquids that mix).
Distillation separates miscible liquids based on their boiling points. The liquid with the lower boiling point will evaporate first. A Liebig condenser is used during distillation. Examples of mixtures that can be separated by distillation are salt and water or water and alcohol.
Thermometer
Liebig condenser
Vapours
Distilling flask
Water out Cold water in Burner
Receiving flask Distillate
:Fig. 17.11 Distillation ? TEST TUBE
6. Suggest a separation technique suitable for the following tasks: • To obtain salt from seawater. • To get pure drinking water from seawater. • To separate sand and seawater. • To determine the dyes used in the coating of sweets.