Question

Describe an activity with diagram to illustrate that the no change in temperature takes place when a liquid convert into a vapour.

Answer 1

heya........

Matter can change from one form to other form i.e from solids to liquids to gases.

The phenomenon of the change of matter from one state to another and back to original state is known as interconversion of the sates of matter.

Matter can be changed from one state to another by changing temperature or pressure.



# Change in state of water
When heat energy is supplied to ice it changes into water and then to vapor. If we cool the steam it gets converted into water and further cooling of water changes into ice.

Here the heat energy is used up in changing the state of matter. the heat is used to increase the kinetic energy of the particles of ice to such an extent that they break away from the rigid lattice structure of the solid form, ice, and move around freely to form the liquid form, water. So, until all the ice has melted, the heat absorbed does not raise the temperature of the ice-water mixture. In the same way the temperature does not change while a liquid is boiling. This heat, which does not raise the temperature of the body, is called Latent Heat.


Melting or Fusion
Melting is the process where solid changes into a liquid at a particular temperature.


Melting point
The temperature at which a solid melts to become a liquid at the atmospheric pressure is called its melting point.

# Melting points of some solids

            Solids        Melting point 

1.  Ice (H2O)    00C   

2.Sodium chloride (NaCl)    8000C 

  3. Iron    15350C

Latent heat
The word 'latent' means hidden. The characteristic amount of energy absorbed or released by a substance during a change in its physical state that occurs without changing its temperature is known as latent heat.

Latent heat of fusion
Latent heat of fusion is the amount of heat energy required to change 1 kg of a solid into liquid at atmospheric pressure at its melting point.


Boiling
Boiling is the process where a liquid  changes into a vapor at a particular temperature.


Boiling point
Water boils at 1000C. At that temperature, it changes from the liquid state to the gaseous state. The temperature at which a liquid starts boiling at the atmospheric pressure is known as its boiling point

# Boiling points of some liquids

               Liquid           Boiling point   

 1.Water     1000C    

2.Chloroform    620C   

 3.Sulphuric acid    2800C

Latent heat of vaporization
Latent heat of vaporization is the amount of heat energy required to change 1 kg of liquid into a gas at atmospheric pressure at the boiling point.


Freezing
The process, where a liquid converts into a solid, is called freezing or solidification.

On cooling a liquid the particles come closer due to the decreased kinetic energy.When the particles come closer the inter particular spaces are reduced and the forces of attractions  increased. Finally the particles are arranged themselves in a regular, compact manner. 


Evaporation
The process where a liquid changes into vapor at any temperature below its boiling point is evaporation .Evaporation is a surface phenomenon. i.e evaporation takes place at the surface of the liquid.

finally hence proved liquid converted into vapour


tysm.....#gozmit

Answer 2

Temperature doesn't change while Boiling This is because that heat is used up as latent heat for changing state of matter .

Explanation:

Suppose we take ice in container at temperature "t".

Now we supply  heat to it , and wait for its melting ,the thermometer still records the same temperature .

We have different states of matter that is :

• Solid
• Liquid
• Gas

These states can be inter-converted by changing the physical conditions .

1. Like on heating ,solid gets converted to liquid , on further heating liquid forms vapors.
2. Similarly , on cooling Gas gets condensed to liquid ,which further changes to solid on cooling .
3. When one state is changed to another , either the heat  is absorbed or given out .
4. This heat is called latent heat or hidden heat that is required for changing state .
5. The heat energy supplied or released , doesn't rise the overall temperature of a substance as all this heat is used up in changing state of matter .

Let us say that we need to change ice into water .

For changing ice into water ,we heat it .This heat is used up in increasing the spaces between particles , decreasing inter-molecular forces .Hence it is used up in changing state and it has no effect on temperature of substance .