8
Formulas and Nomenclature
At first it may seem difficult to learn the formulas and names of the hundreds of
chemical compounds used in the introductory chemistry course. Actually the
job is not so hard if you start in a systematic way, by learning the atomic
building blocks that make up the compounds and the rules for naming the
compounds.*
One of the many ways to classify inorganic compounds is into electrolytes,
nonelectrolytes, and weak electrolytes. When electrolytes are dissolved in water, the resulting solution is a good conductor of electricity; the water solutions
of nonelectrolytes do not conduct electricity; the solutions of weak electrolytes
are very poor conductors. Water itself is an extremely poor conductor of electricity. A flow of current is a movement of electrical charges caused by a
difference in potential (voltage) between the two ends of the conductor.
In metals, electrons are the structural units that carry the electrical charge, a
negative one. But because electrons cannot exist for any significant length of
time as independent units in water, some other kind of charged structural unit
must be present in solutions of electrolytes. The general term for this charged
structural unit is ion. A negatively charged ion is an atom (or a group of atoms)
carrying one or more extra electrons it has received from other atoms. And,
naturally, those atoms or groups of atoms that gave up electrons are no longei
* Most of the rules for chemical nomenclature are discussed in this chapter The approved
system for naming complex ions is given on page 391, and that for naming ortho, meta, and pyro
compounds on page 420.
Formulas and Nomenclature
At first it may seem difficult to learn the formulas and names of the hundreds of
chemical compounds used in the introductory chemistry course. Actually the
job is not so hard if you start in a systematic way, by learning the atomic
building blocks that make up the compounds and the rules for naming the
compounds.*
One of the many ways to classify inorganic compounds is into electrolytes,
nonelectrolytes, and weak electrolytes. When electrolytes are dissolved in water, the resulting solution is a good conductor of electricity; the water solutions
of nonelectrolytes do not conduct electricity; the solutions of weak electrolytes
are very poor conductors. Water itself is an extremely poor conductor of electricity. A flow of current is a movement of electrical charges caused by a
difference in potential (voltage) between the two ends of the conductor.
In metals, electrons are the structural units that carry the electrical charge, a
negative one. But because electrons cannot exist for any significant length of
time as independent units in water, some other kind of charged structural unit
must be present in solutions of electrolytes. The general term for this charged
structural unit is ion. A negatively charged ion is an atom (or a group of atoms)
carrying one or more extra electrons it has received from other atoms. And,
naturally, those atoms or groups of atoms that gave up electrons are no longei
* Most of the rules for chemical nomenclature are discussed in this chapter The approved
system for naming complex ions is given on page 391, and that for naming ortho, meta, and pyro
compounds on page 420.