Chapter 9

Solution Chemistry

Solutions are homogeneous (that is, everywhere the same) mixtures of substances that combine to
form a single phase, generally the liquid phase. Many important chemical reactions, both in the
laboratory and in nature, take place in solution (including almost all reactions in living organisms).

A solution consists of a solute (e.g., NaCl, NH 3 , or C 12 H 22 O 11 ) dispersed (dissolved) in a solvent (e.g.,
H 2 O or benzene). The solvent is the component of the solution whose phase remains the same after
mixing. For example, a solid cube of sugar dissolved in water (a liquid) yields a liquid mixture of
water and sugar: Water is therefore the solvent and sugar the solute. If the two substances are
already in the same phase, the solvent is generally taken to be the component present in greater
quantity. Solute molecules move about freely in the solvent and can interact with other molecules
or ions; consequently, chemical reactions occur easily in solution.

BASIC CONCEPT

solute  = substance being   dissolved   (often  solid)

solvent = substance doing   the dissolving  (often  liquid)

solution    = solvent   +   dissolved   solute

Solvation

Solubility  and Concentration   Units

Dilution

Electrolytes    and Conductivity

Colligative Properties