Lesson Plan

2. Explore potable water - practical

KS4-17-10

Learning Outcomes

Describe how to analyse a sample of water for purity and how to purify a sample of water by distillation

Higher: Can describe how to analyse a sample of water for purity and how to purify a sample of water by distillation
Middle:
Lower:

Activities

Mission Starter - Engage

Method:

Lesson Starter: Salt can be removed from seawater to make it safe to drink. Can you work out a process which could be used which will remove salt from seawater?

Resources:

Lesson Starter Slide

The Story - Explore and Explain

Method:

Answer questions and take part in activities during the presentation. Stop the presentation at the relevant slides: Talk Partners; AfLs; Songs. Take part in the Choral Response Questions activity (see Assessment section) after the Keywords/Rocket Words slide.

Resources:

Presentation Sticky notes

Mission Expert - Explain

Method:

A worker from Thames Water explains how does Thames Water encourage people to treat water with care and respect?

Michael Holland from Thames Water shows us how water samples are tested for ammonia.

Resources:

Expert Film

Mission Assignment - Elaborate

Method:

Watch Mrs Peers-Dent show you how to test water for sodium and chloride ions before and after distilling. Complete a Water Purification & Testing - GCSE Science Required Practical (Triple) - 

Analysis and purification of water samples from different sources, including pH, dissolved solids, and distillation.

Resources:

Mission Assignment Slide

Handout

Mission Log - Evaluate

Method:

Quiz With their talk partners, the children are to go through the quiz at the end of the presentation and answer the questions. Formative Assessment Forms Students are to complete these forms where present. Assessment Trays Ask the children to place their Handouts, notebooks, Formative Assessment Forms, Investigation Sheets, into either the Discover tray or Explorer tray * Explain that the green tray means that the learner has understood the lesson well, and that the red tray means that the learner needs more time to practise. * use whichever colours of tray you have in stock, or prefer to use for this. Children to take interactive Assessment Quiz to test lesson comprehension.

Resources:

Quiz in presentation Formative assessment forms Assessment trays Interactive quiz

Assessment

Questions to Ask During the Lesson

Define the terms:

  • potable water
  • pure water

Teacher Mastery

Water of appropriate quality is essential for life. For humans, drinking water should have sufficiently low levels of dissolved salts and microbes. Water that is safe to drink is called potable water. Potable water is not pure water in the chemical sense because it contains dissolved substances.

The methods used to produce potable water depend on available supplies of water and local conditions.

In the UK, rain provides water with low levels of dissolved substances (fresh water) that collects in the ground, in lakes, and rivers and most potable water is produced by:

  • choosing an appropriate source of fresh water
  • passing the water through filter beds 
  • sterilising.

Sterilising agents used for potable water include chlorine, ozone, or ultra-violet light.

If supplies of fresh water are limited, desalination of salty water or sea water may be required. Desalination can be done by distillation or by processes that use membranes such as reverse osmosis. These processes require large amounts of energy.

Curriculum Fields

National Curriculum

Distinguish between potable water and pure water. Describe the differences in treatment of ground water and salty water. Give reasons for the steps used to produce potable water.

Working Scientifically Skills

Carrying out experiments appropriately, having due regard to the correct manipulation of apparatus, the accuracy of measurements and health and safety considerations