Question

How would you perform an activity to find out the effect of a change in temperature?

Answer 1

Step-1:

Classification of the matter based on the physical state:

Based on the physical state, all the matter can be classified into three groups namely solid-state, liquid state, and gaseous state or vapor state.

Step-2:

Ways to change the physical state of matter:

We can change the physical state of matter in two ways as follows

1. By changing the temperature
2. By changing the pressure

The effect of a temperature change:

1. Temperature is a major factor responsible for causing a change in the state of matter.
2. On heating a solid substance, the substance melts and converts into a liquid state.
3. It has been observed that temperature remains constant until all solid melts into a liquid.
4. Similarly, when the liquid substance is heated the liquid state gets converted into the gaseous state.

Step-3:

An activity to find out the effect of a temperature change:

Procedure:

1. Take about 150 g of ice in a beaker.
2. Suspend a laboratory thermometer so that its bulb is in contact with the ice as shown in the figure given below.
3. Start heating the beaker on a low flame.
4. Note the temperature when the ice starts melting.
5. Note the temperature when all the ice gets converted into water.
6. Record your observations for this conversion of solid to liquid state.
7. Put a glass rod in the beaker and stir it till the water starts boiling.
8. Keep a careful eye on the thermometer reading till most of the water has vaporized.
9. Record your observations for the conversion of water in the liquid state to the gaseous state.

Experimental set-up to show the effect of temperature change:

Step-4:

Observation:

1. On increasing the temperature of solids, the kinetic energy of the particles increases.
2. The particles start vibrating with greater speed due to the increase in kinetic energy.

Step-5:

Conclusion:

1. The energy supplied by heat overcomes the forces of attraction between the particles.
2. The particles leave their fixed positions and start moving more freely.
3. A stage is reached when the solid melts and is converted into a liquid. This stage is called the melting point of the solid.