Page 4 - 10-Chem-11 Organic Chemistry
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11. Organic Chemistry eLearn.Punjab
Though, the oxides of carbon like carbon monoxide and carbon dioxide, carbonates,
bicarbonates and carbides are also carbon compounds, they are not treated as organic
compounds because their properties are quite different from those of organic compounds.
Each organic compound has specific formula.
There are four types of formulae of organic compounds:
• Molecular formula
• Structural formula
• Condensed formula
• Dot and cross formula
(i) Molecular Formula
The formula which represents the actual number of atoms in one molecule of the organic
compound is called the molecular formula, e.g., molecular formula of butane is C4H10. It shows:
a. Butane is made up of carbon and hydrogen atoms.
b. Each molecule of butane consists of 4 carbon atoms and 10 hydrogen atoms.
(ii) Structural Formula
Structural formula of a compound represents the exact arrangement of the different atoms
of various elements present in a molecule of a substance. In a structural formula, single
bond is represented by a single line (-), a double bond by two lines (=) and a triple bond by
three lines ( ) between the bonded atoms. Organic compounds may have same molecular
formulae but different structural formulae, e.g., structural formulae of butane C4H10 are:
(iii) Condensed Formula
The formula that indicates the group of atoms joined together to each carbon atom in a
straight chain or a branched chain is called the condensed formula.
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