Question

a) Definition of terms.Please briefly give the meaning of each of the following terms:

1. colligative property 2. vapor pressure 3. semi-permeable membrane 4. osmosis 5. dialysis

Answer 1

Colligative property - A property by virtue of which it is independent of the nature and molecular mass and size rather depends only on the number of particle present. for example, lowering of vapour pressure, elevation in boiling point etc

Vapour pressure- It is the pressure exerted by the vapours of the substance in vapour phase which is in dynamic equilibrium with the substance in liquid phase with in a closed container.

Semi-permeable membrane- It is a membrane which allows only the solvent molecule to pass throuhgh it and give no permission to the solute molecules.

Osmosis- When two solution of different concentration are separated by a semi permeable membrane, solvnets tend to flow from the solution of lower concentration to that of higher concentration. this phenomenon of solvent flow is called as osmosis and osmosis is also a colligative property.

Dialysis- In contrast to osmosis where only solvent flows, in dialysis some dissolved ions pass through the membrane. It isa purification technique usually employed to purify blood in case of kidney failure.