Chemistry ( Chapter 1 and 2 ) MM.40
1. Why does a gas fill completely the vessel in which it is kept?
2. Why should we call a wooden table a solid?
3. Convert the following into Celsius scale: (i). 293 K (ii). 470K
4. Solids are normally not compressible. Why can a sponge be readily pressed?
5. A rubber band changes its shape when stretched. Can it be regarded as solid?
 6. Give reason: Water is liquid at room temperature whereas an iron almirah is solid?
7. Explain why there is no rise in temperature of a substance when it undergoes a change of state although it is still being heated?
 8. What is solid CO2?
9. How does pressure help in the liquefication of a gas?
 10. When sugar is dissolved in water, there is hardly an increase in volume. Which characterstic of matter is illustrated by this observation?
11. Two liquids differing in boiling point by at least 200 present in a mixture can be separated by fractional distillation. Explain.
 12. Fog and cloud are both colloidal in nature. How do they differ?
 13. Colloidal solutions show Tyndall effect but true solutions do not. Why?
14. How will check the purity of a pure chemical compound in the solid state?
 15. Sodium chloride contains two elements, but it is still a pure substance. Why?
16. Fresh air cannot be regarded as a pure substance. Why?
17. Butter is an example of one type of colloidal solution. Name it. Give reason for your choice.
18. Compare the particle sizes in a true solution, colloidal solution and suspension.
 19. A mixture of ethyl alcohol and water is homogeneous while that of oil and water is heterogeneous. Explain.
20. How can a saturated solution be made unsaturated?