What is Organic chemistry?
Is the branch of chemistry that deals with the study of the chemistry of carbon and its compounds except oxides, carbonates and hydrogen carbonates. The three (oxides, carbonates and hydrogen carbonates) are studied under inorganic chemistry.
All organic compounds contain
carbon together with one or more other elements such as hydrogen, oxygen,
chlorine, nitrogen and sulphur. These organic compounds range from simple
molecules such as methane, ethene, ethyne, giant molecules such as
Deoxyribonucleic acid (DNA),rubber, cotton, drugs, insecticides, explosives and
photographic films- of which all these compounds are of great importance in
everyday life.
Organic chemistry is also the
foundation for basic studies in botany, nutrition, agriculture, pharmacy,
technology, forestry, zoology.
Occurrence of carbon.
Carbon is a fundamental element that exists naturally in various forms and compounds. It is the sixth most abundant element in the earth crust. Carbon has atomic number of 6, consisting of 6 protons, neutrons and 6 electrons. It is allotropic in nature and forms both amorphous and crystalline carbon. Amorphous carbon mainly exists in the form of coal, and wood charcoal (charcoal). Other forms of amorphous carbon include coke, sugar charcoal, animal charcoal. Carbon is also isotopic, forming carbon-12, carbon-13 and carbon-14, of which carbon-12 is the most abundant element and carbon-14 is the radioactive used in nuclear reactions.
Uniqueness of Carbon
Carbon behaves differently from the rest of the group members due:
- Very small atomic radius
- Having high electronegativity
- Lack of vacant orbital
- Having a maximum covalency of 4
- High bond energies of the C-C and C-H bonds.
- It
forms a stable multiple bonds with itself and with other non-metals. These
include carbon-carbon double bonds (
) carbon-carbon triple bonds (
) or bonds between carbon and other
elements such as oxygen (
) sulphur (
) and nitrogen (
)
- Carbon can form a number of hydrocarbons because it can catenate. Catenation is the ability of the element to form bonds between atoms of the same element.
- It forms gaseous oxides unlike other members
- The halides are stable to hydrolysis.
Characteristic properties of organic compounds
Most organic compounds are:
- Covalently bonded and generally gases, volatile liquids and low melting point solids with few elements such as carbon, hydrogen, sulphur, nitrogen and halogens
- Low melting and boiling point compounds
- Generally insoluble in water except those with polar functional groups such as -OH, -COOH, -SO3H
- The reactions are generally slow although some are explosive, and most reactions require catalysts
إرسال تعليق