In the red

1 Name three indicators.

2 What colour would purple litmus go if you mixed it with:

a) sulphuric acid

b) tap water

c) lemon juice?

7Ec

In the red3 A few drops of litmus solution were

added to some toothpaste. The litmus turned blue. What does this tell us about toothpaste?

7Ec

In the red4 Sally crushed up some purple berries

from a bush, and mixed them with a little water. When she mixed the juice with some washing powder, it changed colour to red.

a) Is the berry juice acting as an indicator? Explain your answer.

b) Which of these best describes the washing powder? A-definitely an acid; B-definitely not an acid; C-possibly an acid. Explain your answer.

7Ec

In the red1 Name three indicators.

For example: red cabbage, blackberry juice, tea and universal indicator.

7Eb

In the red2 What colour would purple litmus go if

you mixed it with: a) sulphuric acid

red

b) tap water

stay purple

c) lemon juice?

red

7Ec

In the red3 A few drops of litmus solution were

added to some toothpaste. The litmus turned blue. What does this tell us about toothpaste?

Toothpaste is not an acid, it is an alkali.

7Ec

In the red4 Sally crushed up some purple berries

from a bush, and mixed them with a little water. When she mixed the juice with some washing powder, it changed colour to red.

a) Is the berry juice acting as an indicator? Explain your answer.

Yes (probably) – it has changed colour when mixed with another chemical.

7Ec

In the red4 Sally crushed up some purple berries

from a bush, and mixed them with a little water. When she mixed the juice with some washing powder, it changed colour to red.

b) Which of these best describes the washing powder? A-definitely an acid; B-definitely not an acid; C-possibly an acid. Explain your answer.

7Ec

In the red

C – you cannot be certain on the evidence presented. Sally would have to test the juice with a known acid before interpreting the colour change.

7Ec