Acids and Alkalis
Are all acids dangerous??
Lemons
Are pretty good….
Are all acids dangerous??
Everyday Acids
Laboratory
Acids
Alkalis are another group of chemicals
opposite to Acids
Everyday Alkalis
Laboratory Alkalis
Ph Scale and Universal Indicator
Stronger Acid
1
2
Strong
acid
3
4
Stronger Alkali
5
Weak
acid
6
7 8 9
neutral
10 11 12
weak
alkali
13 14
Strong
alkali
Experiment to investigate the pH of different household items
1
2 3
4
Strong
acid
5 6
7
8 9 10 11 12 13 14
Weak neutral
acid
Strong
alkali
weak
alkali
Name of
Substance
Colour
Change
pH
Acid, Alkali or
Neutral?
Orange juice
Light Yellow
4
Weak Acid
Cancelling out acids and alkalis Neutralisation
By mixing an acid solution with an alkali solution in the
correct amount, we can cancel them out.
The solution formed is neutral. (It has a pH of 7.)
When we cancel out an acid and alkali like this, we
neutralise them. This is called neutralisation.
ACID + ALKALI = NEUTRAL
Make your own pH scale
Colour your pH scale in correctly
Cut Out the Labels and stick next to
the correct pH Value
1
2 3
Strong
acid
4
5 6
7
Weak neutral
acid
8 9 10 11 12 13 14
weak
alkali
Strong
alkali
• You will be given a team name, nominate
one person to be the spokesperson
• When you have discussed the answer as a
team the spokesperson puts the team name
up
• The winning team gets a prize!!!!!!!!!