https://docs.google.com/file/d/0B-KzsIWUtWHcenJmWGdINjhvRjQ/edit
https://docs.google.com/file/d/0B-KzsIWUtWHcVDBGeURwOGhBdHM/edit
Solution
Notes
Solutions - a
homogeneous mixture of two or more substances in which the molecules or atoms
of the substances are completely dispersed at the molecular or ionic level.
Consisting of 2 parts – the solvent and solute. Solutions are formed when
solvent molecules break apart the solute.
Solvent – the substance that does the dissolving. Usually, it is
the larger part and a liquid.
Solute – the substance that is being dissolved. Usually, it is the
smaller part and can be a solid, liquid or gas.
Characteristics of a Solution:
1. The
solute does not settle out even if left for long periods of time.
2. It is
transparent; no particles can be seen in the solvent; it won't disperse light.
3. It can
be different colors.
4. The
solute can't be separated out by filtering; both solvent and solute pass
through filter paper.
Solubility
– the ability of substance to be dissolved into another substance.
Factors that affect solubility:
Nature of the substances – substances that are similar will form
solutions, polar vs. non-polar, “like dissolves like”
Temperature – increased kinetic energy
Solids – more solid can dissolve because the solute molecules move
apart and stay disconnected.
Gases- less gas can dissolve because more
molecules can escape the solution.
Pressure – only affects gases.
Pressure “pushes” the molecules into the solution and prevent them from
escaping.
Factors the affect the rate of solubility:
Surface area – increased
access of solvent molecules to solute molecules.
Stirring and temperature – increased kinetic energy
increases collisions between solvent and solute.
Types of solution
Saturated – the maximum
solute that can be dissolved into the solvent at a given temperature.
Unsaturated – the
solution contains less solute than can be dissolved at a given temperature.
Supersaturated
– the solution contains more solute than the maximum. If disturbed the solute will crystallize
and fall out of solution.
Solubility curve – graph of the
relationship between temperature and solubility depicting saturation points.
Other
important terms
electrolyte = a
substance that dissolves in water to give a solution that conducts electric
current
nonelectrolyte = a
substance that dissolves in water to give a solution that does NOT conduct an electric
current
colloid =
microscopic particles that are too large to be dissolve into solutions and instead
suspended
suspension = a heterogeneous
mixture in which the particles are so large that they settle out unless the
mixture is constantly stirred or agitated
Tyndall effect = when
light is reflected and scattered by the suspended colloid particles.
Miscible = molecules "mix" together
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