First Semester 2021-22                                                Chemistry 9

Practice questions Unit 1 : The particulate nature of matter.

Name : …………………………………………… ……   Date :…………………………………

 

1. Describe the three states of matter in terms of shape and volume.

2. Describe the difference between solids and liquids in terms of closeness and motion of particles.

3. Explain why liquids cannot be compressed.

4. Name these changes of state:

Gas to liquid:

Liquid to gas below the boiling point:

Solid to gas:

5. Use the kinetic particle theory to explain why a balloon increases in size when the temperature increases.

6. Explain using ideas of particles and energy, the changes in arrangement and motion of the particles which occurs when zinc melts.

7. Describe the evidence for the kinetic particle theory.

8. Define and explain the term diffusion using kinetic particle theory.

9. Explain why hydrogen gas, H_{2 ,} diffuses quicker in air than hydrogen sulfide gas,H₂S

10. The wall of a rubber balloon is slightly porous. Gases can move through the wall. A balloon contains a mixture of carbon dioxide and helium. Explain why the percentage of carbon dioxide in the balloon increases with time.