Alkenes. Bonding. The electron configuration of carbon is. 1s 2 2s 2 2p 2. When carbon bonds in alkenes, the electron configuration changes. 1s 2 2s 1 2p 3.
The electron configuration of carbon is
When carbon bonds in alkenes, the electron configuration changes
The 2s electron and two of the 2p electrons combine to form three sp2 hybrid orbitals, leaving a spare p-orbital on each of the carbon atoms
A hybrid orbital from each carbon overlaps to form a σ-bond
The p-orbitals overlap causing areas of electron density spanning across the top and the bottom of the σ-bond joining the two carbon atoms.
This is the π-bond.
If an alkene is bubbled through concentrated HCl(aq) at room temperature, a monosubstituted chloro-alkane is formed.
When steam and a gaseous alkene are passed over a solid phosphoric acid catalyst (H3PO4) at 600K and 6MPa, alcohols are formed.
If a gaseous alkene and H2 gas are passed over a finely divided nickel catalyst at high pressure and temperature (420K and 500kPa for making margarine!) an alkane is formed.