Reactions of alkenes

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
• a…