What is the pH scale, and why do we need an understanding of pH in everyday life?

1. Learning Goals:
To understand what pH is
To understand what the colours and numbers
on the pH scale mean
To understand the pH of some household
examples

2. 1.Name an acid
2.What element is common to all acids
3.Name a base
4.What makes a base different from an acid?

6. 1 2 3 4 5 6 7 8 9 10 11 12 13 14
Neutral
Equal
H+ and
OH-

7. Hydrochloric Acid
H+
H+
Cl
Cl
Cl
H+
 All acids contain (H+) in solution.
 pH is a fancy measure of the number
of H+ ions in solution (but backward)
 What will sort of number will an acid
with lots of H+ give us?

8. 1 2 3 4 5 6 7 8 9 10 11 12 13 14
Strong
Weak
acid
acid
Lots of H+
Less of H+
The more H+
the solution
has, the smaller
the pH number

9. Sodium Hydroxide
 Bases don’t contain H+.
 The more OH- is in the base, the less
space there is for H+ in solution
 A weak base contains few OH-… what
will that mean about the pH?
Na
OH-
OH+
Na
Na
OH-

10. 1 2 3 4 5 6 7 8 9 10 11 12 13 14
The more OH+
the solution
has, the less H-,
The bigger the
pH number is
Less of H+
Weak
Strong
base
base
Very Little H+

13. pH Quiz rules:
2 teams (either girls Vs boys or sides
of the room
First side with a hand up
If first hand up doesn’t get it, the
question goes to the other team

14. Banana
pH 5

15. Battery
Acid
pH 0

16. Beer
pH 4

17. Bicarbonate
of Soda
pH 8

18. Bleach
pH 13

19. Blood
pH 7.5

20. Coke
pH 3

21. Drain Cleaner
pH 14

22. Hand Soap
pH 10

23. Lemon Juice
pH 2

24. Milk
pH 6

25. Orange Juice
pH 3

26. Pure Water
pH 7

27. Saliva
pH 6

28. Sea Water
pH 8

29. Stomach Acid
pH 2

30. Toothpaste
pH 9

31. Urine
pH 6