lesson: acids and bases. science differentiation in action all acids have a sour taste. carbonic...

Lesson: Acids and Bases

Science Differentiation in action

All acids have a sour taste.

Carbonic acid Citric acid

Science Differentiation in action

Some acids are corrosive.

(H2SO4) (HCl)

What elements are contained in these acids?

Sulfuric acid. Hydrochloric acid.

Science Differentiation in action

Which hazard symbol represents corrosive?

A B C

Science Differentiation in action

How would we test for an acid?

Try some experiments.

Use litmus paper.

What did you find out?

Acids turn blue litmus paper ____red.

Science Differentiation in action

Bases are the opposite of acids.

Toothpaste Soap Cleaning agents

Science Differentiation in action

Strong bases include:

What elements are contained in these bases?

(NaOH) Ca(OH)2

Sodium hydroxide Calcium hydroxide

Science Differentiation in action

Strong bases include:

Sodium hydroxide is also called caustic soda because it is

corrosive.

Calcium hydroxide is also called limewater.

NON-CORROSIVE

Science Differentiation in action

Bases that dissolve in water are called:

So ______ are bases soluble in water.alkalis

Alkalis

Science Differentiation in action

How would we test for a base or an alkali?

Try some experiments.

Use litmus paper.

What did you find out?

Alkali turn red litmus paper ____.blue

Science Differentiation in action

The strength of acids and bases can be measured on a pH scale.

Each colour represents a number on the pH scale.

Strong acid

Weak acid

Weak base

Strong base

1 3 5 7 9 11

12 14

pH 7 is neutral.It is not an acid or a

base.

Science Differentiation in action

Each colour represents a number on the pH scale.

We can measure pH using universal indicator.

Strong acid

Weak acid

Weak base

Strong base

1 3 5 7 9 11

12 14

pH 7 is neutral.It is not an acid or a base.

Science Differentiation in action

Each colour represents a number on the pH scale.

Now, use universal indicator to find the pH of some substances.

Strong acid

Weak acid

Weak base

Strong base

1 3 5 7 9 11

12 14

Science Differentiation in action

1. What acid is found in your stomach?

Review Questions

2. Which pH is neutral?

3. What would you use to measure pH?

1 3 5 7 9 11

12 14

Science Differentiation in action

What happens when you add an acid to a base?

Question to think about!