.1.

CLASS -9 REVISION -LESSON -1

Name the property of gases due to which it is possible to fill CNG in cylinders for using as fuel in cars.

2.

List any two properties of particles of matter.

3.

When camphor is heated in a China dish, it changes into gas without changing into liquid. What is the name given to this change of state?

4.

Why light is not considered as a matter?

5.

On suffering from fever which will lower down your body temperature, more ice or ice cold water? Why?

6.

Ice, water and steam are three states of a substance and not different substances. Justify.

7.

Change the following celsius temperatures to kelvin scale:
(i) – 273 °C (ii) – 100 °C
(iii) – 40 °C (iv) + 30 °C

8.

State which property of gas is used in supplying oxygen cylinder to hospitals?

9.

Out of honey or ink which will diffuse faster and why?

10.

Give reasons for the following:
(a) Camphor disappears if kept in open air for a few days.
(b) Wet clothes do not dry easily on a rainy days.
(c) We sweat more on humid days.

11.

Give reasons for the following:
(a) Why does Ice float on water?
(b) Why does a gas fill completely the vessel in which it is kept?
(c) Latent heat of evaporation of two liquids A and B is 100 J/kg and 150 J/kg respectively. Which one can produce more cooling effect and why?

Rohan observed vendor making Kulfi without the fridge, he asked his friend Ravi how is it possible. Ravi explained he uses a mixture of ice and common salt for making Kulfi without a fridge.
(a) What are the values associated with Ravi?
(b) What is the temperature of mixture of ice and common salt?
(c) What is this mixture called?