A homogenous mixture of two or more substances with
uniform composition is called solution. A solution
has two components, solute and solvent. A solute is
the substance which is dissolved and is in smaller
quantity while a solvent is the substance in which a
solute is dissolved and is in larger quantity.
There are nine types of solutions depending upon the
nature of solute and solvent. If solvent is liquid
then the solution is considered as true solution.
A solution in which the amount of the solute is less
than it has the capacity to dissolve in large
quantity of solvent is called unsaturated solution.
The solution which contains maximum amount of solute
in a given solvent at a specific temperature and no
more solute dissolves in it is called saturated
solution. In a saturated solution there is a dynamic
equilibrium between dissolved and un dissolved
A super saturated solution contains greater amount
of dissolved solute than that are present in a
saturated solution. It is obtained by dissolving
solute in saturated solution on heating. More solute
would dissolve on heating saturated solution.
The solubility is defined as the amount of solute in
gram dissolved at a given temperature in 100 gram of
the solvent. Many factors affect the solubility of a
solute in a solvent which are temperature, pressure
(for gases), nature of solute and solvent. Generally
the solubility of a solute increases with-the rise
in temperature except gases whose solubility
decreases with the rise in temperature. The
solubility of gases in a solvent is generally less,
but the solubility of gases increases with increase
in pressure and is directly proportional to
pressure applied. It is governed by Henery's law.
Nature of solute and solvent also affects on the
solubility. It is well known fact that like
Crystallization is the process in which dissolved
solute comes out of the solution and forms crystals.
Crystals are homogenous solids bounded by plane
faces, having sharp edges, regular and
definite-shapes. They have sharp melting points.
Crystallization may occur by the process of
evaporation or by cooling heated solution. In a
solution the amount of solute dissolved in a given
quantity of solvent is known its concentration. The
solution that contains less amount of solute as
compared to the amount of solvent is known as dilute
solution and the solution that contains greater
amount of solute as compared to the amount of the
solvent is known as "concentrated solution".
The different units in which the concentrations of
the solutions are expressed are molarity, molality,
mole fractions, percent concentrations.
Molarity is defined as the number of moles of the
solute, dissolved per dm3 or liter of the solution.
It is denoted by M.
Molality is defined as the number of moles of the
solute, dissolved per kg or 1000 gram of the
solvent. It is denoted by m.
Mole fraction is defined as the ratio of moles of
solute or solvent to the total moles of the
solution. It is denoted by X.
For example =No. of moles of solute/
Total moles of
solute and solvent in the solution
Percent concentration is based on mass (M) and
volume (V) of the components solute and solvent in
the solution. There are four different ways in which
percent concentration can be expressed.
% M/M: %M/V: %V/M: %V/V:
A suspension is a mixture in which particles are of
one or more substances having size larger than 1000
nanometer (n.m) (1000 n.m or 1000 xl09m). In
suspension the solute particles are not soluble in
solvent and can be removed by filteration because
the solute Particles are big enough to pass from the
pores of filter papers. Suspension is heterogeneous.