Importance of Functional Groups in Organic Chemistry

While organic chemistry is considered as the branch ofdissolve in water than are inorganic compounds.
chemistry in which the compounds of carbon are4. Organic compounds are likely to be more flammable
studied,  the name organic goes back to a muchbut poorer conductors of heat and electricity than are
earlier time in history when chemists thought thatinorganic compounds.
chemical compounds in living organisms were5. Organic reactions tend to take place more slowly
fundamentally different from those that occur inand to produce a much more complex set of products
nonliving things. Their belief was that the chemicals thatthan do inorganic reactions.
could be extracted from or that were produced byThe huge number of organic compounds requires that
living organisms had a special "vitalism" or "breath ofsome system be developed for organizing them. The
life" given to them by some supernatural being. Ascriterion on which those compounds are organized is
such, they presented fundamentally different kinds ofthe presence of various functional groups. A functional
problems than did the chemicals found in rocks,group is an arrangement of atoms that is responsible
minerals, water, air, and other nonliving entities. Thefor certain characteristic physical and chemical
chemical compounds associated with living organismsproperties in a compound. For example, one such
were given the name organic to emphasize theirfunctional group is the hydroxyl group, consisting of an
connection with life. In 1828, German chemist Friedrichoxygen atom and hydrogen atom joined to each other.
Wöhler, who found a very simple way to convertIt is represented by the formula —OH. All organic
chemical compounds from living organisms intocompounds with the same functional group are said to
comparable compounds from nonliving entities, provedbelong to the same organic family. Any organic
that this theory of vitalism was untrue. Consequently,compound that contains a hydroxyl group, for instance,
the definition of organic chemistry changed as a resultis called an alcohol. All alcohols are similar to each
of Wöhler's research. The new definition was basedother in that: (1) they contain one or more hydroxyl
on the observation that every compound discovered ingroups, and (2) because of those groups, they have
living organisms had one property in common; they allsimilar physical and chemical properties. For example,
contained the element carbon. As a result, the modernalcohols tend to be more soluble in water than other
definition of organic chemistry, as the study oforganic compounds because the hydroxyl groups in
compounds of carbon, was adopted.the alcohol form bonds with water molecules.
One important point that Wöhler's research showedThe simplest organic compounds are the
was that the principles and techniques of chemistryhydrocarbons, compounds that contain only two
apply equally well to compounds found in livingelements: carbon and hydrogen. The class of
organisms and nonliving things. Nonetheless, somehydrocarbons can be divided into subgroups depending
important differences between organic and inorganicon the way in which carbon and hydrogen atoms are
(not organic) compounds exist. These include thejoined to each other. In some hydrocarbons, for
following:example, carbon and hydrogen atoms are joined to
1. The number of organic compounds vastly exceedseach other only by single bonds. A single bond is a
the number of inorganic compounds. The ratio ofchemical bond that consists of a pair of electrons.
carbon-based compounds to non-carbon-basedSuch hydrocarbons are known as saturated
compounds is at least ten to one, with close to 10hydrocarbons. In other hydrocarbons, carbon and
million organic compounds known today. The reasonhydrogen atoms are joined to each other by double or
for this dramatic difference is a special property of thetriple bonds. A double bond consists of two pairs of
carbon atom: its ability to join with other carbon atomselectrons, and a triple bond consists of three pairs of
in very long chains, in rings, and in other kinds ofelectrons. The symbols used for single, double, and
geometric arrangements. It is not at all unusual fortriple bonds, respectively, are —, =, and ?.
dozens, hundreds, or thousands of carbon atoms toHydrocarbons containing double and triple bonds are
bond to each other within a single compound—asaid to be unsaturated. Hydrocarbons can also be
property that no other element exhibits.open-chain or ring compounds. In an open-chain
2. In general, organic compounds tend to have muchhydrocarbon, the carbon atoms are all arranged in a
lower melting and boiling points than do inorganicstraight line, like a strand of spaghetti. In a ring
compounds.hydrocarbon, the carbons are arranged in a continuous
3. In general, organic compounds are less likely toloop, such as a square, a pentagon, or a triangle.