Starter quiz
The equipment setup shown below shows which separation technique?- decanting
- filtration ✓
- distillation
- chromatography
-
Match each letter on the diagram below to the correct label.- a⇔filtrate ✓
- b⇔funnel ✓
- c⇔filter paper ✓
- d⇔residue ✓
- A single element or compound that is not mixed with any other substance is said to be ______.
- 'pure' ✓
- A substance that dissolves into another substance is described as ______.
- 'soluble' ✓
- When a substance dissolves into a liquid (e.g., water), a __________ forms.
- suspension
- solution ✓
- solute
- solvent
-
- Which of the following techniques can be used to fully isolate components of a mixture or solution?
- decanting
- filtration ✓
- distillation ✓
- crystallisation
-
Exit quiz
- Water is essential for life. Which of the following are domestic uses of water?
- watering crops
- washing laundry ✓
- hydrating farm animals
- cooking ✓
-
- All sources of water contain varying amounts of micro-organisms and what other material?
- insoluble solids
- salt
- dissolved substances ✓
-
- Water that is safe to drink is classified as ______.
- 'potable' ✓
- Match each step of making potable water, from either groundwater or freshwater, to the correct description.
- screening⇔a grid acts like a sieve, removing large insoluble objects ✓
- sedimentation⇔small, insoluble particles 'settle out', forming a sediment ✓
- filtration⇔very small particles are removed by passing through fine layers ✓
- sterilisation⇔microbes are killed ✓
- Which of the following could be used to sterilise a water sample to ensure it is potable?
- chlorine ✓
- ultraviolet (UV) light ✓
- ozone ✓
- hydrogen
-
- Put the following stages of creating potable water from groundwater or freshwater in the correct order.
- 1⇔screening
- 2⇔sedimentation
- 3⇔filtration
- 4⇔sterilisation
Worksheet
Presentation
Video
Lesson Details
Key learning points
- 'Potable' and 'pure' water are not the same material.
- Water used in analysis must not contain any dissolved ions.
- The method used to obtain potable water depends on the water source.
- Filtration and sterilisation are used to obtain potable water from groundwater and fresh water sources.
- Desalination of sea water creates potable water by distillation or reverse osmosis.
Common misconception
Pupils tend to think that all water is the same. Pupils tend to forget that non-visible substances are also found in water.
Stress that pure water only contains H₂O molecules. Other waters may include varying amounts of dissolved salts, other solids or micro-organisms. Stress that microbes must be killed for water to be potable, but are too difficult to remove.
Keywords
Pure - A single element or compound that is not mixed with any other substance.
Potable - Water that is safe to drink.
Sterilisation - The process of killing bacteria and other living microorganisms.
Desalination - The process of removing dissolved salts from seawater.
Reverse osmosis - The movement of solvent through a semipermeable membrane by applying excess pressure on the solution. This process can remove dissolved solutes from water.