1. Acids and Alkalis
Aim:
To understand the properties of acids and alkalis
To identify different chemicals as acid or alkali

2. Safety
Some of the chemicals you will be using in this topic are HAZARDOUS.
You may find various symbols on the bottles containing the acids and alkalis
What do they mean?
Corrosive

3. What do these hazard symbols mean?
Harmful
Irritant
Flammable
Toxic

4. Properties of Acids
Strong acids are corrosive and can ‘eat away’ at materials like metal, stone and flesh!
Weak acids like lemon and vinegar taste sour.
Acids contain hydrogen (but not all things that contain hydrogen are acids)

5. Acids
You will often find these acids in the science lab, however they can also be found naturally. Where else may you find them?

6. What type of acid do these contain?
Citric acid
Phosphoric acid
Ethanoic acid
Tannic acid
Lactic acid

7. Properties of Bases and Alkalis
They feel soapy to touch
They are soluble bases
Like acids they can ‘burn’ the skin
Alkalis contain hydroxide ions
They taste bitter

8. Alkalis
In the science lab you will often find these alkalis. Alkalis are also present in these objects:
Indigestion tablets
Wasp stings
Cleaning products
Soap
Baking soda
Toothpaste

9. Using Indicators
Aim:
Use a range of different indicators to identify acids and alkalis.
Explain the advantages and drawbacks of different indicators.

10. Using Indicators
Indicators work by changing to one colour in acids and another colour in alkalis
There are many different indicators, in this experiment you are going to test a few and record what colour they turn in an acidic, alkaline and neutral solution.
During the experiment you will need to remember that sodium hydroxide is alkaline, hydrochloric acid is acidic and water is neutral

11. Results and Conclusion

12. Homework
Make a display showing the examples of acids and alkalis you use in your home. You could:
Cut out pictures from the internet.
Use labels from cans, jars and bottles.
Cut out pictures from magazines and newspapers.

13. Universal Indicator Aim:
Use Universal Indicator to identify acids and alkalis.
Use the pH scale to identify the strength of different acids and alkalis.

14. The Universal Indicator scale

15. Practical Work Name of Substance Colour in U.I pH Number
Acid, Alkali or Neutral?

16. Universal Indicator Mystery
Aim:
Use universal indicator to identify some mystery solutions.

17. Universal Indicator Mystery

18. Results Table
Solution
Colour in U.I pH
Label A B C D E

19. Making an indicator Aim: Make an indicator from a natural source.
Use your indicator to identify a range of acids and alkalis.
Evaluate and decide which indicator is the best and explain why.

20. Making an Indicator
Proper pH indicator solution or paper is expensive!
We can make our own, less-expensive pH indicator solution or paper using certain flowers, fruits and vegetables.
Each table will be making a range of different indicators from different sources and testing each one to find out which is the best!

21. Results Table Indicator Colour in Acid Colour in Alkali
Colour in Neutral
Red Cabbage
Beetroot
Red Onion

22. Neutralisation Aim: Explain what the term Neutralisation means.
Interpret graphs.
Identify some everyday examples of neutralisation.

23. What colour will the universal indicator turn in these substances?

24. Neutralisation

26. Neutralisation Q1. What is the pH of Sodium Hydroxide?
Q2. What is the pH of Hydrochloric acid?
Q3. What volume of Sodium Hydroxide had to be added to neutralise the acid?

27. Everyday examples of Neutralisation

28. Everyday examples of Neutralisation

29. Everyday examples of Neutralisation

30. Everyday examples of Neutralisation

31. Aim: Investigate what the products of a neutralisation reaction are.

32. The Products of Neutralisation
Mix together an acid and alkali in an evaporating basin.
What two things need to be kept the same?
The Concentration and Volume of the acid and the alkali needs to be the same.
Using a bunsen burner, tripod, heat proof mat and gauze. Heat the evaporating basin.
What will evaporate from the basin?
What will be left in the basin?
Water
A salt

33. Aim: Revise the topic ready for your end of unit test.
Revision
Aim:
Revise the topic ready for your end of unit test.

34. Tim and Moby Revision video