Acids and Alkalis - Identifying pH with Indicators

• Science
• Lower Secondary (Key Stage 3)

Acids and Alkalis

Sort the keywords into the correct box.

Acid

Alkali

Both

Sour

Bitter

Irritant

Corrosive

Lemons

Vinegar

Toothpaste

Soap

Bleach

Wear googles

Mrs Walker dissolves 3 spoons of coffee powder in some hot water to make her morning cup of coffee.

Solute:

Solvent:

Solution:

Coffee powder

Hot water

Strong coffee

A mixture of a substance (solid, liquid or gas) and a liquid.

A substance (solid, liquid or gas) that is dissolved in a liquid.

A liquid in which a substance dissolves.

Match the words to the definitions.

Solvent

Solute

Solution

Which solution is more concentrated?

1. A
2. B

Which solution is more concentrated?

1. A
2. B

Which solution is more concentrated?

1. A
2. B

Which solution is more corrosive?

1. A
2. B

Put the acids in order from most dilute to most concentrated.

Dilute

Concentrated

How could you make this solution more concentrated?

Name a weak acid

Name a strong acid

Name a weak alkali

Name a strong alkali

Solution            Colour         pH

pH 14

pH 4

pH 1

pH 10

pH 7

Purple

Red

Green

orange

Blue

Sort the keywords into the correct box.

Acid

Alkali

Sour

Bitter

pH 10

pH 1

Red - Orange

pH 5

pH above 7

pH 8

Blue- Purple

pH Below 7

This acid is...

1. Weak
2. Strong

This acid is...

1. Weak
2. Strong

This acid is...

1. Weak
2. Strong

Match the keyword to the definition.

Lots of acid particles in less solvent.

Few acid particles in lots of solvent.

All the acid particles split up when dissolved.

Some acid particles split up when dissolved.

Concentrated

Dilute

Strong

Weak

Match each diagram to the correct description.

strong & dilute

strong & concentrated

weak & dilute

weak & concentrated

How would you make a dilute acid solution?

A pupil has a dilute solution of weak lemon juice and a concentrated solution of strong bleach. What hazard symbol should she use to label each solution? Explain your choice.