1. Is it possible to liquefy atmospheric gases? If yes, suggest a method?
2. A sponge can be pressed easily still it is called a solid. Why?
3. Give reasons:-
Watervapour have more energy than water at same temperature?
4. Liquids generally have lower density as compared to solid. But you must have observed that ice floats on water. Why?
5. What happens when a liquid is heated?
6. A gas can exert pressure on the walls of the container. Assign reason?
7. When pressure on the surface of the gas is increased what will happen to the interparticle forces?
8. What happen when an iron nail is put in copper sulphate solution? Give the equation of the reaction involved?
9. Define latent heat of Vaporization?
10. Define latent heat of fusion?
11. What is dry ice?
12. Name two substances that show sublimation?
13. Give two examples of diffusion?
14. Distinguish between evaporation and boiling?
15. Why do we see water droplets collected on the outer surface of a glass container containing ice?
16. Why is water liquid at room temperatures?
17. Athul had parked his bicycle in the sunny day on the parking stand in his school campus.When the school got over Athul saw his burst cycle tyre thereafter he kept less air in his cycle tyres and did not inflate them fully.
a) Why did the tyre burst?
b) Why is air compressible?
c) What value of Athul is reflected in the above act?
18. Sita lived in a village and could not afford refrigerator in her house. She knew how to keep water cold and pressure all perishable items in her house. She kept wet cloth surrounding the earthen pot to keep water cool,she also kept vegetables fresh by keeping them in wet gunny bag and timely sprinkle water over it.
a) Why did Sita keep wet cloth surrounding the earthen pot?
b) Suggest one more method of keeping the house cool in summer?
c) What value of Sita is reflected in the above case?
Ms. S. Sobhana Kumari, (PGT Chemistry)