The reactivity of the C=C double bond
Alkenes are more reactive than Alkanes because of the C=C double bond. The average bond enthalpies for a C-C single bond (+347) and C=C double bond (+612). Bond enthalpies measure the strength of covalent bonds.
- In an alkane, the single bond between 2 carbon atoms is a -bond
- In an alkene, the double bond between 2 carbon atoms is made up of -bond and a -bond
The strength of the -bond is seen through the difference between the single C-C bond and the C=C bond which is 612-347 = 265 kJ mol (to the power of -1). The bond enthalpies show that:
- a double bond is stronger than a single bond; and