Question

4. State the main postulates of kinetic theory of
matter.
9,
5. What happens to water if
(a) it is kept in a deep freezer ?
(b) it is heated ?
Explain the phenomenon of change of state
of water.
6. (a) State the law of conservation of mass.
(b) What do you observe when barium chloride
solution is mixed with sodium sulphate
solution ?​

Answer 1

Explanation:

The main points for the kinetic theory of matter are

1. The solids have least kinetic energy while the gases have the most kinetic energy in them
2. Kinetic energy of particle increases with an increase in temperature.
3. More the intermolecular space more the kinetic energy.

Q.5. (a) When the water is kept in a deep freezer , the kinetic energy of the particles of water decreases as there is decrease in temperature.

Due to which their intermolecular spaces reduces and it turns solid i.e. ice.

(b) When the water is heated the kinetic energy if their particle increases with the increase in temperature due to which their intermolecular spaces increases and the water changes from liquid state to gaseous state

(6), (a) The law of conservation of mass states that the mass of reactants is equal to the mass of products formed during a chemical reaction.

FOR EXAMPLE :- C + O2 ----> CO2

Here the mass of C + O2 is equal to the mass of CO2 formed

(b) When barium chloride and sodium sulphate solution are mixed then double displacement / precipitation reaction takes place, which is represented as

AB + CD -----------> AD + CB

SO on the above basis,

Barium sulphate (White precipitate) + Sodium chloride

will be formed

where barium sulphate will act an insoluble white

matter floating / settle on the solution as white matter which is termed as white precipitate.