Before you start your investigation you should carry out a risk assessment and have it checked by your teacher. For help with this, read through our health and safety information and look out for health and safety warnings in the text.
In this project you will find out about the causes and consequences of dehydration. You will devise some experiments to investigate the constituents of commercially available oral rehydration salts (ORS), a common treatment for dehydration.
You should start by doing some research to find out about the causes and consequences of dehydration. Find out about how to treat dehydration including the use of oral re-hydration salts (ORS) and what they contain.
Testing oral rehydration salts
Buy a number of commercially available oral re-hydration salts (for example, Diarolyte) from your local pharmacy and carry out experiments to confirm that the ORS contains the active ingredients that the manufacturer claims.
Most re-hydration salts contain glucose and salt (sodium chloride). Devise experiments to test that your sample contains these ingredients.
- You might want to use the Benedict’s test to check for glucose. This is a standard test for glucose – you will find the instructions in most GCSE Biology/Science text books – ask your teacher for help.
- Pure water is an electrical insulator but becomes a conductor when salts (like sodium chloride) are dissolved in it. You could use a battery and an ammeter to set up a circuit to check the electrical conductivity of your samples of ORS. You could compare your measurements with the electrical conductivity of distilled / de-ionised water and with a salt solution that you have made up yourself. From this you should be able to arrive at some conclusions about the presence of salt in the ORS.
Are there any hazards in the chemicals, equipment or procedures you will use? How can you reduce the risks from them?
You will need to think about whether you should test the ORS as a powder or made up into a solution according to the instructions on the packet or to some other strength.
You will need to present and comment on the results of your research and your tests on the ORS.
For a similar project at Silver level try ‘Comparing oral re-hydration therapies’
STEM-based competition for primary and secondary schools in the Leicestershire, South Nottinghamshire, Bracknell Forest and Wokingham areas.
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