1. Lesson CSI
Acids and alkalis

2. Acids and Alkalis
Learning objective – To be able to distinguish between acids and alkalis
Success Criteria
Level 5 - Identify a solution as acid or alkali using an indicator
Level 4 - Give examples of indicators that can be used to classify acids and alkalis.
Level 4 - Record your results on a table
Level 3 - Recognise common hazard symbols.
Level 3 - Be able to name some common acids

6. Match the meaning to the hazard symbol
poisonous/toxic
Corrosive
irritant
flammable

7. Names of acids Hydrochloric Citric Ethanoic acid Sulphuric
Vinegar
Ethanoic acid
Sulphuric
Phosphoric acid
Nitric

9. Some common acids
Three acids are particularly common in the laboratory .
Acid
Formula
hydrochloric
HCl
sulphuric
H2SO4
nitric
HNO3
These are strong acids that should be treated with the greatest respect.

10. Indicators: acid or alkali?
An indicator is a dye which changes colour according to whether it is in an acidic or alkaline solution.
Litmus is an indicator that is red in acid and blue in alkali.

11. Litmus Test TEACHER’S NOTES Results of the litmus test are : alkali
acid
water

12. Testing using litmus Substance Colour change with red litmus
Colour change with blue litmus
Acid or alkali A B C