1.4 CHAPTER 1. ORGANICMOLECULES
C C C C C
C
C
C
Figure 1.2: A branchedcarbon chain- Because of its positionon the Periodic Table, most of the bonds that carbon forms
with other atoms are covalent. Think for example of aC-C bond. The difference
in electronegativity between the two atoms is zero, so this is a pure covalent
bond. In the case of aC-H bond, the difference in electronegativitybetween
carbon (2.5) and hydrogen (2.1) is so small that C-H bonds are almost purely
covalent. The result ofthis is that most organiccompounds are non-polar. This
affects some of the properties of organic compounds.
1.4 Representing organic compounds
ESCD
There are a number ofways to represent organic compounds. It is useful to know all
of these so that you canrecognise a molecule however it is shown. There are three
main ways of representing a compound. We will use the example of a molecule called
2-methylpropane to helpexplain the difference between each.Molecular formula ESCE
The molecular formulaof a compound shows how many atoms of eachtype are in a
molecule. The numberof each atom is writtenas a subscript after the atomic symbol.
The molecular formula of 2-methylpropane is: