Starter quiz
- What is the main principle behind the separation of mixtures in distillation?
- Differences in boiling points ✓
- Differences in melting points
- Differences in solubility
-
- Why can't filtration separate soluble substances from liquids?
- Filtration is only for gases
- Filtration is too slow
- Soluble substances pass through the filter ✓
-
- What does a change in the boiling point of a liquid indicate?
- Change in temperature
- Improper measurement
- Presence of impurities ✓
-
- What does filtration separate?
- Gases from liquids
- Insoluble substances from liquids ✓
- Soluble substances
-
- What is condensation?
- The change of state from gas to liquid ✓
- The change of state from liquid to gas
- The change of state from solid to gas
-
- How can boiling point data be used?
- To assess the purity of water samples ✓
- To measure the volume of liquids
- To separate insoluble substances
-
Exit quiz
- What process would produce pure water from potable water containing dissolved solids?
- Filtration
- Evaporation
- Distillation ✓
- Chlorination
-
- What does a boiling point range of 98°C to 102°C suggest about the water sample?
- The sample contains impurities ✓
- The sample is improperly measured
- The sample is pure
-
- What is indicated by a boiling point of 100°C?
- Impure water
- Incorrect measurement
- Pure water ✓
-
- What is the purpose of the condenser in the distillation apparatus?
- To heat the mixture
- To heat the vapour
- To cool and condense the vapour back into a liquid ✓
-
- Why is it important to collect the distillate in a clean container?
- To avoid contamination of the distillate ✓
- To ensure the distillate evaporates again
- To measure the volume accurately
-
- How can you determine the effectiveness of distillation from boiling point data?
- Check the colour of the distillate
- Compare the boiling points before and after distillation ✓
- Measure the volume of the distillate
-
Worksheet
Loading worksheet ...
Presentation
Loading presentation ...
Video
Lesson Details
Key learning points
- Distillation can be used to purify water samples.
- Boiling point data can be analysed to assess the purity of water samples.
- The more impurities present in a sample, the larger the temperature range over which the water will boil.
- Pure water boils at 100°C.
Common misconception
All water samples boil at 100°C.
If a water sample is impure, the boiling point of water increases. The greater the amount of impurities in a water sample, the larger the temperature range over which it boils.
Keywords
Impurity - A chemical that is found in a material in very small amounts, but can change the material's properties.
Pure - A single element or compound that is not mixed with any other substance.
Sample - A smaller portion of a larger quantity of a substance.
Distillation - A separation technique that uses boiling and condensation to remove and isolate a liquid component of a mixture.
Distillate - The liquid that is condensed from the gas state during distillation.
+