A solution is
a homogeneous mixture composed of two or more substances. The substances
can be solids, liquids, or gasses. The substance that makes up most of the
solution is called the solvent. If the solvent is water, then the
solution is called an aqueous solution. The minor components of the
solution are called solutes. For example, if we dissolve 2 grams of
sugar and 4 grams of salt in 2 L of water, water is the solvent while sugar and
salt are solutes. This would be an example of an aqueous solution. Since
living organisms are composed mostly of water, studying the chemistry of life
largely involves studying the chemistry of aqueous solutions. Therefore,
preparing aqueous solutions is an essential skill in molecular and cellular
biology labs. A third way to describe the concentration of a solution is
by molarity. With molarity, the amount of solute present is measured in
units called moles rather than grams or milliliters. How much is a mole? One mole
(1 mol) of any
