7b. pH scale from S2

Question 1

What does the pH scale measure?

Answer 1

The acidity or alkalinity of a substance

Question 2

What is the number range of the pH scale?

Answer 2

1-14

Question 3

What is the colour range for the pH scale?

Answer 3

Question 4

What is the pH range for acids?

Answer 4

Less than 7

Question 5

Do strong acids have a higher or lower pH than weak acids?

Answer 5

Lower

Question 6

What is the pH range for alkalis?

Answer 6

Greater than 7

Question 7

Do strong alkalis have a higher or lower pH than weak alkalis?

Answer 7

Higher

Question 8

What is the pH value for neutral solutions?

Answer 8

7

Question 9

True or false? The pH scale can only measure in whole numbers.

Answer 9

False

Question 10

What is an indicator?

Answer 10

A substance that changes colour to identify pH values

Question 11

How do we test a substance for pH using universal indicator?

Answer 11

​1. Substance must be in aqueous solution

2. Place a few drops of indicator solution into a small volume of the substance.

3. Compare and match the colour to appropriate colour chart

4. Read off correct pH value for that colour

Question 12

What are some natural sources of indicators?

Answer 12

Plants, fruits and flowers

Question 13

How do you make red cabbage indicator?

Answer 13

Question 14

What is the colour scale for red cabbage indicator?

Answer 14

Question 15

Name 3 indicators used in the lab

Answer 15

pH paper universal indicator red cabbage indicator