UNITS OF CONCENTRATION
There are many ways to express concentrations. Concentration may be expressed several different ways and some of the more common concentration units are:
1. Equivalent weight
2. Molarity
3. Molality
4. Normality
5. Percent solution (weight/weight)
6. Percent solution (weight/volume)
7. Percent solution (volume/volume)
Equivalent Weight
The equivalent weight is determined by dividing the atomic or molecular weight by the valence. A major use of the concept of equivalents is that one equivalent of an ion or molecule is chemically equivalent to one equivalent of a different ion or molecule. The mass of a substance especially in grams is chemically equivalent to eight grams of oxygen or one gram of hydrogen :
the atomic or molecular weight divided by the valence Valance could be determined as
1. The absolute value of ion charge
2. The number of H+ or OH– that a species can react with
3. The absolute value of change in charge on a species when undergoing a chemical reaction.
