A solution is a homogeneous mixture of gases, solids, or liquids in which the individual molecules
of two or more substances are evenly dispersed throughout the medium (solution). For example, if
one dissolves sucrose in water, the sugar granules will break down into individual molecules.
Parts of Solution
Solvent : The first part is the solvent, which is defined as that
portion of the solution that is either in greatest concentration or the portion of the
solution that is doing the dissolving. Water is usually considered to be the universal solvent,
no matter what proportion of the solution it is.
Solute : Its the other part of the solution . It is the substance thats mixed with solvent to frame a solution.
Solution = Solvent + Solute
Colloidal Solution ::
A colloidal solution is not a true solution since the individual molecules are not
mixed on a molecular basis;
hence, the solution is
not homogeneous throughout. This type of solution contains
aggregates of molecules with each individual aggregate being denoted as a colloid
or as a colloidal particle. The number of molecules in each aggregate may be from
several hundred to a few thousand. The size of each colloidal particle is usually
in the range of
from 1 to 200 nanometers (nm) in diameter.
Saturated Solutions ::
This type of solution is defined as a solution in which
the dissolved
solute is in equilibrium with undissolved solute. At a given temperature,
most solutions can dissolve (hold) only a given number of solute particles.
Unsaturated Solutions ::
An unsaturated solution is one that does not contain all the solute
molecules that the solution could possibly "hold."
Emulsions ::
Emulsions are colloidal solutions in which the dispersed phase and the dispersion
medium are
immiscible. If one mixes water and oil together and then shakes the container,
the oil will break into very small particles that will disperse within thewater.
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Solubility
Solubility is the measure of how much solute can dissolve in a given amount of solvent.
Factors that have an effect on solubility are
the nature of the solute and solvent,
temperature and pressure. An increase in temperature, increases the solubility of a
solid solute. When the solution is a gas, the solubility decreases as the temperature
rises. Changes in pressure, usually have no effect for a solid and a liquid. It does
have an effect on gaseous solutes. An increase in pressure increases solubility.
The concentration of dissolved gas depends on the partial pressure of the gas.
The partial pressure controls the number of gas molecule collisions with the
surface of the solution. If the partial pressure is doubled the number of
collisions with the surface will double.
The increased number of collisions
produce more dissolved gas.
Low Pressure Equilibrium
High Pressure
Low Concentration
Higher Concentration
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