Question

5
Q.4 Give reasons for the following:
1. All solutions are homogenous mixtures of a solute in a solvent.
Inors
Includes
Example
calcium
2. Hardness in temporary water can be removed by boiling, but hardness in permane
hard water cannot.
3. Colloidal solutions exhibit brownian movement.
Other c
4. The percentage of oxygen, in air dissolved in water, is higher than the percentage
5. Washing soda can be used to remove both temporary and permanent hardness in water
2. OCCU
oxygen in ordinary air.
Carbon​

Answer 1

Answer:

Homogeneous mixtures have a uniform composition and solute dissolves uniformly in a solvent forming a homogeneous mixture.

The temporary hardness in water is due to bicarbonate of calcium or magnesium, which decomposes on boiling into CO^2CO

2

which does not dissolve in water and can be separated. Permanent hard water contains [SO_2]^{2-}or\ Cl^-[SO

2

]

2−

or Cl

−

which cannot be removed by boiling.

Particles of colloidal solutions are in continuous motion.

Oxygen dissolves in water and in air, but the air has some other gases also, some gases dissolve in water.

It exchanges ions [SO_4]^-\ or\ Cl^-[SO

4

]

−

or Cl

−

and does not make water hard