- Fill in the blanks by using following words:
- Lemons and limes taste ……………
- They contain …………. acid.
- This acid is a ………….. acid.
- Litmus turns ………….. in acids.
- Litmus turns ……………in alkalis.
- Litmus turns purple when it is in a ………………….. substance.
[6]
8. Match the following substances with type os substances:
| Substance |
| Sodium hydroxide |
| Water |
| Lemon juice |
| Type of Substance |
| Neutral |
| Acid |
| Alkali |
[3]
9. Write ‘True’ for the statements you consider as true and ‘False’ for the incorrect statement:
(a) Universal Indicator changes colour and shows the pH of a substance ……..……………..
(b) A pH of below 8 is alkaline ……………………….
(c) When you mix acid and alkali together they make an acidic solution. ……………………
[3]
10. Name three common weak acids.
……………………………………..
……………………………………..
……………………………………..
[3]
11. What should you do if you spill acid?
………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………
[3]
12. Name three common alkalis found in our daily use items.
……………………………………………………….
……………………………………………………….
……………………………………………………….
[3]
13. Complete the following table with the colour of Universal Indicator:
| Type of substance | Colour of Universal Indicator |
| Strongly acidic | |
| Weakly acidic | |
| Neutral | |
| Weakly alkaline | |
| Strongly alkaline |
[5]
14. Write three examples of neutralisation in practical life.
……………………………………………………………………..……………………
…………………………………………………………………………………….……
…………………………………………………………………………………………
…………………………………………………………………………………………
[3]