08. In the Red

Outcomes:

- State what an indicator is.

- Give two examples of indicators and state what happens to them in acids/alkalis.

Activity

1. Complete the sentences using the words in bold.

a Litmus is an _______________.

b Litmus turns in acids ______________.

c Strong acids that attack metals, stonework and skin are said to be __________________.

corrosive indicator red

2. What colour would the solutions below turn litmus? Colour the solutions in the test tubes the colour they would turn if litmus were added.

3. Complete the sentences using the words in bold.

a Alkalis turn litmus __________.

b They feel to touch ___________. Many alkalis are too ______________ to touch.

blue dangerous soapy

4. Each test tube has had litmus added to it. Complete the word below each test tube to tell you what sort of substance was in the tube to start with.

5. A neutral substance is neither acid nor alkali. Colour the acids red, the alkalis blue and the neutral substances purple in the boxes.