Nomenclature of Carbon Compounds Containing Functional Groups

Nomenclature of Carbon Compounds Containing Functional Groups

We have millions of organic compounds. As number of organic compound is very big it is difficult to remember their names individually.To overcome this problem they have to be properly named. For this, the International Union of Pure and Applied Chemistry (IUPAC) had been formed, and one of its responsibilities is to name the organic and inorganic compounds in a systematic order. The basic idea behind the systematic nomenclature is that there should be only one name for the given structure
throughout the world and also there should be only one structure for the given name.

IUPAC stands for International Union of Pure and Applied Chemistry. IUPAC names are used for International communication. Rules for IUPAC Naming of Organic Compounds :
(i)   Select the possible longest chain containing the functional group.

e.g.

Nomenclature of Carbon Compounds Containing Functional Groups 1, longest chain contains 5 carbon atoms.
Nomenclature of Carbon Compounds Containing Funcional Groups 2, longest chain contains 4 carbon atoms.

(ii)  The number of carbon atoms in the parent compounds is denoted by proper prefix :

Meth for one     eth for two     Prop for three
but for four       pent for five         hex for six
hept for seven    oct for eight          non for nine

e.g., in CH3–CH2–CH2–CH2–CH2–CH3 the parent chain contains 6 Carbon atoms, it is called
Hexane. ane is the suffix for alkanes (saturated hydrocarbons) having single bonds only.

(iii) Groups attached to the parent chain are indicated by their names and prefixing the number of carbon to which they are attached in parent chain.

Alkyl group         CH3— is called methyl
has general          C2H5—is called ethyl
formula CnH2n+1   CH3CH2CH2— is called n-propyl

Example.

Nomenclature of Carbon Compounds Containing Funcional Groups 3
is called 2-methylpropane because methyl group is attached to second carbon atom.

(iv) The counting of carbon chain is done in such a way that the carbon attached to the alkyl group or functional group gets the minimum number, e.g.,
Nomenclature of Carbon Compounds Containing Funcional Groups 4 is 2-methylbutane and not 3-methylbutane.

(v)  If more than one identical groups are attached to same or different carbon atoms, prefix the numbers of carbon to which they are attached. The number of these groups are indicated as : di for two, tri for three, tetra for four and so on, e.g.
Nomenclature of Carbon Compounds Containing Funcional Groups 5 2, 2-dimethylpropane because there are two methyl groups (dimethyl) and both are attached to second carbon therefore 2, 2-dimethylpropane because parent carbon chain contains three carbon atoms Similarly,
Nomenclature of Carbon Compounds Containing Funcional Groups 6 is 2, 3-dimethylbutane

(vi) For double bond in alkenes suffix-ene, for triple bond suffix-yne is used in alkynes. In alkenes and alkynes, number of carbon atoms after which double or triple bond is present is also prefixed, e.g.,
Nomenclature of Carbon Compounds Containing Funcional Groups 7 is but-2-ene because double bond is after second carbon atom.

Read More:

What are carbon compounds?

What are carbon compounds?

  1. Carbon compounds are compounds which contain the element carbon.
  2. These compounds contain carbon and hydrogen only or carbon and hydrogen in combination with a few other elements such as oxygen, sulphur, nitrogen, halogens and phosphorus.

Organic compounds

  • Carbon compounds can be classified into two groups:
    (a) Organic compounds
    (b) Inorganic compounds
  • Chemists define organic compounds as carbon- containing compounds. However, some exceptions to this definition are
    (a) oxides of carbon such as carbon monoxide, CO and carbon dioxide, CO2
    (b) carbonates such as calcium carbonate, CaCO3
    (c) hydrogen carbonates such as sodium hydrogen carbonate, NaHCO3
    (d) cyanides such as potassium cyanide, KCN
    (e) metallic carbides such as aluminium carbide, Al4C3
  • Inorganic compounds include all non-carbon-containing compounds and the few carbon- containing compounds just mentioned.
  • Table shows examples of organic and inorganic compounds found in nature.
    What are carbon compounds 1
  • Most organic compounds contain the elements carbon and hydrogen. Hence, complete combustion of organic compounds produces carbon dioxide and water.
  • The following equation shows the complete combustion of glucose, C6H12O6.
    What are carbon compounds 2

Complete combustion of organic compounds experiment

Aim: To investigate the complete combustion of organic compounds.
Materials: Ice, ethanol, palm oil, limewater, water.
Apparatus: Beaker, boiling tubes, rubber stoppers with two holes, delivery tubes, rubber tubing, filter funnel, filter pump, spirit lamp, Bunsen burner, thermometer, test tube holder, retort stand and clamps, wooden blocks.
Procedure:

  1. A spirit lamp is filled with some ethanol and the apparatus is set up as shown below.
    What are carbon compounds 3
  2. The spirit lamp is lit to let the ethanol burn. At the same time, the filter pump is turned on.
  3. Changes taking place in boiling tubes A and B are noted and recorded.
  4. After about 15 minutes, the filter pump is turned off and boiling tube A is removed.
  5. The liquid inside boiling tube A is heated until it starts to boil. The boiling point of the liquid is recorded.
  6. Steps 1 to 5 are repeated using palm oil to replace ethanol.

Observations:

  1. The colourless liquid in boiling tube A boils at 100°C.
  2. The limewater turns milky.

Discussion:

  1. When an organic compound is burnt in excess oxygen,
    (a) the carbon combines with oxygen to form carbon dioxide.
    C + O2(g) → CO2(g)
    (b) the hydrogen combines with oxygen to form water.
    4H + O2(g) → 2H2O(g)
  2. Carbon dioxide is detected through its ability to form a white precipitate with limewater.
  3. When a liquid boils at 100°C and 1 atmospheric pressure, it is pure water.

Conclusion:
Complete combustion of an organic compound produces carbon dioxide and water.

People also ask

Hydrocarbons

  • Hydrocarbons are the simplest of all organic compounds, containing only carbon and hydrogen.
  • Hydrocarbons are classified into two groups:
    (a) Saturated hydrocarbon
    (b) Unsaturated hydrocarbon
  • Saturated hydrocarbon molecules are made entirely of carbon-carbon single bonds. Saturated hydrocarbons contain only single covalent bonds.
  • Unsaturated hydrocarbon molecules contain at least one carbon-carbon double or triple bond. Unsaturated hydrocarbons contain multiple bonds.
    Example:
    What are carbon compounds 4
  • The most common natural sources of hydrocarbons are petroleum, coal, natural gas and certain trees such as the rubber tree.
  • Non-hydrocarbons are organic compounds in which some or all of the hydrogen atoms have been replaced by other atoms such as oxygen, nitrogen, phosphorus or halogens.
    For example,
    What are carbon compounds 5
    (a) sugar is a compound of carbon, hydrogen and oxygen.
    (b) protein contains carbon, hydrogen, oxygen and nitrogen.
    (c) tetrachloromethane contains carbon and chlorine.