(40) GCSE Chemistry Revision "Simple Distillation"

Introduction to Simple Distillation

• Physical separation technique used to separate a dissolved solid from a liquid while retaining the liquid.

• Distillation works by evaporating the liquid and then condensing the vapor back to liquid.

Crystallization vs. Simple Distillation

Crystallization

• Used to separate solids dissolved in a liquid.

• Example: Sodium chloride in water.

• Process: Heat the solution to evaporate water, leaving behind solid crystals.

Simple Distillation

• Alternative method when the liquid needs to be conserved after separation.

• Example: Could be used to produce drinking water from seawater (though it requires a lot of energy).

Two Stages of Simple Distillation

1. Evaporation

• Heat the solution using a heat source (e.g., Bunsen burner).

• The liquid turns into vapor.

2. Condensation

• Vapor travels up a glass tube, passing over a thermometer where its temperature increases.

• The vapor enters a condenser, which is cooled by circulating cold water.

• Vapor condenses inside the condenser to form liquid.

• The liquid is collected in a beaker, while solid crystals remain in the original flask.

Apparatus for Simple Distillation

• Flask: Holds the solution with dissolved solid.

• Glass Tube: Continuous passage for vapor to travel.

• Condenser: Cools vapor and facilitates condensation.

• Thermometer: Measures the temperature of the vapor during the process.

Key Points

• Simple distillation requires a heat source and a cooling mechanism (condenser).

• Energy-intensive method not commonly used for producing drinking water, due to high energy costs.

Revision Resources

• Further questions and practice can be found in the provided revision workbook.