1. Our new topic is: 7E Acids and alkalis

2. Title: 7Ea Diamonds are for safety Date: 03/12/2018 Keywords: acids, corrosive, hazard
Draw and label the hazard symbols below.
5 mins
Which symbols do you think can be associated with acids?

3. What does this hazard symbol mean?

4. What does this hazard symbol mean?

5. What does this hazard symbol mean?

6. What does this hazard symbol mean?

7. What does this hazard symbol mean?

8. 7Ea –Diamonds are for safety
We are learning today:
Recall the hazard symbols that are associated with acids. (Grade C)
Describe how to work safely in the science laboratory. (Grade B)
Explain why it is important to label chemicals with safety symbols. (Grade A)

9. VIDEO!
Watch the video and write down the name of the acid that is used!

10. Acids
Concentrated acids react with cotton: They can also react in a similar way with your skin. Concentrated acids are corrosive. We make them safer by diluting them with water.

11. Acids The three acids that we use in science are: Hydrochloric acid
Sulfuric acid
Nitric acid

12. Transporting chemicals
Why do you think that this tanker has to have a warning symbol? Write down your ideas.
Video on active book page 65 – dealing with hazards

13. TASK!
Using your HSW Y7 textbook. Find out ways that we use the three most common acids and write them in your note book! Extension*-Write down any things in your house which you think might contain acids!

14. KNOWLEDGE SHARE!
Hands up! Can you tell the teacher different ways that the acids can be used?

15. Safety in science
Make a poster (1 page in your book) to show how acids should be handled in the laboratory.
Use the following pictures and titles to help you.

16. HOMEWORK!
Look around your house and see if you can find out if the objects on the worksheet contain “acid” or are, “without acid”.

17. Knowledge Check Name three common acids. (3)
What is another word for strong acids? (1)
How do we make acids weaker?
What is the process of making acids weaker called? (1)
Give one use of each type of acid. (3)

18. Title: 7Ea Comparing acids Date: 03/12/2018 Keywords: acids, corrosive, hazard
3 mins
We will be doing a practical today involving acids. Write down 3 basic safety precautions we must follow.

19. 7Ea –Diamonds are for safety
We are learning today:
Recall the three most common acids (Grade C)
Describe what happens to magnesium strips and marble strips in different concentrations of acid. (Grade B)
Explain which acids they believe were the most concentrated based upon their observations. (Grade A)

20. Practical – comparing acids
A Fill a test tube about one third full of acid X. B Put one of the pieces of magnesium into the tube. C Watch what happens. Write your observations in the table. D When the fizzing stops, measure the temperature of the liquid. E Put acid Y into a second tube. F Put another piece of magnesium into this tube. G Now put acid Z into a third tube. H Do the experiment again using acid Z. Record your results. I When the tests are finished, pour all the liquids away. J Refill the three tubes with fresh acids X, Y and Z. K Do the tests again, using marble chips instead of pieces of magnesium.
This practical looks at finding out which acid is most hazardous – X, Y or Z by looking at the reactivity.
You must wear safety glasses and behave in a sensible manner at all times during this experiment. When you have finished, wash your test tubes and put any equipment away that you have used.

21. Practical - what did you see?
Acid
Solid
What happened?
Temperature at the end of the experiment (°C) X
Magnesium Y Z
Marble chip

22. Conclusion - comparing acids
Conclusions explain what you find in an experiment. A good conclusion explains what you found using scientific ideas. Write a conclusion for todays experiment using the guide below: I think the most hazardous acid was…. The least hazardous acid was… I think this because…
This practical looks at finding out which acid is most hazardous – X, Y or Z by looking at the reactivity.

23. Title: 7Eb Tangy Tastes Date: 03/12/2018 Keywords: acid, citric acid, scurvy
Discuss with the person next to you:
‘All acids are dangerous’
Write down your opinion.
3 mins

24. 7Ea –Diamonds are for safety
We are learning today:
Recall how the tastes of acids and alkalis is described (Grade C)
Describe positives and negatives of phosphoric acid in fizzy drinks. (Grade B)
Explain which acid helped save the lives of 15th century sailors and how. (Grade A)

25. Acids
List the acids that are in these drinks.

26. Acids
Some acids are actually safe enough to eat or drink. They are very dilute (very watered down). They are added to fizzy drinks to make them ‘tangy’ and to improve the flavour.

28. Knowledge Check! Where can you find phosphoric acid?
Why is phosphoric acid used?
Why might phosphoric acid be bad for you?
How can you reduce the damage done by phosphoric acid to your teeth?

29. Scurvy
Watch the video on scurvy and then use page 66 in the textbook to explain how citric acid was useful for 15th century sailors.

30. Vinegar
Vinegar is also an acid. The chemical name for vinegar is ‘ethanoic acid’ but usually the labels on vinegar bottles say ‘acetic acid’, this is an old name for vinegar. We use vinegar for flavouring and preserving foods.

31. Think about what we did at the start of the lesson: ‘All acids are dangerous’ Has your opinion changed? Write your ideas in your book.

32. TASK!
Produce a poster which explains the advantages and disadvantages of using acids! Extension*-Write a letter to the boss of Coca Cola explaining to him the dangers of phosphoric acid and how he can help reduce tooth decay.

33. Title: 7Ec In the red: Indicators Date: 03/12/2018 Keywords: indicator, litmus, acid, alkali
Two beakers have been left in a science lab unattended and unlabeled. How could we test to see if the chemicals are acidic? Write down your ideas.
3 mins

34. 7Ec – In the red: Indicators
We are learning today:
What an alkali is
How to test substances to see if they are acidic/alkali using indicators
The colour that litmus turns when different substances are added to it

35. Indicators
An INDICATOR is a special chemical that changes to a different colour in an acid or an alkali. Indicators allow us to test chemicals to see if they are acid or alkali.

36. Acids and alkalis
Food that tastes sour contain ACIDS and food that tastes bitter contains ALKALIS. We can describe what acids and alkalis are using the pH scale. Indicators allow us to tell the difference between acids and alkalis.
ACIDS
NEUTRAL
ALKALIS
Universal indicator solution was used in the pictures.

37. Copy and complete…
An ________ is a special chemical that we can use to test other chemicals to see if they are _____ or _______. An indicator changes to a ________ colour in an acid or ______. acid alkali indicator different alkali

38. Litmus turns red in acid.
The indicator we are using today is LITMUS
Litmus paper and litmus solution are examples of indicators.
Litmus turns red in acid.
Litmus turns
blue in alkali.

39. Practical
Put 2-3 drops of the substance you are testing in the spotting tile. Drop in a small piece of litmus paper.
Liquid
Colour of litmus paper
Acid/
alkali
Saltwater, lemon juice, cola, fairy liquid, water, orange juice,
acid
neutral
alkali

40. Results acid neutral alkali Liquid Colour of litmus paper Acid/ alkali
Salt water
Lemon juice
Cola
Fairy liquid
Water
acid
neutral
alkali

41. Homework: Find out about universal indicator
Homework: Find out about universal indicator. Search ‘universal indicator KS3’