Miscellaneous

Question 1

State the law of Conservation of Mass in a reaction.

1 mark

Answer 1

The mass of the reactants must always equal the mass of the products.

Question 2

Write word equations for complete combustion and incomplete combustion.

4 marks

Answer 2

Complete
Hydrocarbon (fuel) + Oxygen ====> Water + Carbon dioxide

Incomplete
Hydrocarbon + Oxygen ====> Carbon monoxide + Carbon + Water

Question 3

How do you light and use a Bunsen burner safely?

4 marks

Answer 3

When lighting it, light it on the safety flame with the air hole fully closed. When heating something, use the heating flame with the air hole fully open.

Question 4

Distinguish between a control, independent and dependent variable.

3 marks

Answer 4

A control variable is a variable that must be kept the same throughout the experiment.
An independent variable is the one that you change.
A dependent variable is the variable that is influenced by the independent and control variables.

Question 5

List the most common chemistry apparatus.

20 marks

Answer 5

1. Measuring cylinder
2. Tripod
3. Gauze
4. Bunsen burner
5. Funnel
6. Watch glass
7. Test tube
8. Boiling tube
9. Beaker
10. Conical flask
11. Clamp stand
12. Crucible
13. Pipe clay triangle
14. Round-bottomed flask
15. Tongs
16. Bungs
17. Spatula
18. Pipette
19. Spotting tile
20. Test tube rack