Different ways of Expressing concentration:

There are several ways of expressing concentration of a solution----

a) Percent by weight

b) Mole fraction

c) Molarity

d) Molality

e) Normality

Types of solutions:

Types of solutions:

Substances in any three states of matter (solid, liquid, gas) can act as solute or solvent. Thus there are following types of solutions—

State of solute	State of solvent	Example
1. Gas	Gas	Air
2. Gas	Liquid	O2 in water, CO2 in water(Carbonated drinks)
3. Gas	Solid	Absorption of H2 by palladium
4. Liquid	Liquid	Alcohol in water
5. Liquid	Solid	Mercury in silver
6. Solid	Liquid	Sugar, salt
7. Solid	Solid	Carbon in iron(Steel)

Solutions

Definitions:
A solution is a homogenous mixture of two or more substance on molecular level whose composition can be varied over certain ranges. The constituent of the mixture present in a smaller amount is called the Solute and the one present in a larger amount is called the Solvent. For example, when a small amount of sugar (solute) is mixed with water (solvent), a homogenous solution in water is obtained.

Concentration is generally expressed as the quantity of solute in a unit volume of solution. A solution containing a relatively low concentration of solute is called Dilute solution. A solution of high concentration is called Concentrated solution.