Alkanes are saturated (only contain single bonds) hydrocarbons (only contain hydrogen and carbon)
The single bonds in Alkanes are σ bonds.
σ bonds can rotate freely
σ bonds are the overlap of orbitals directly between the two nuclei.
Alkanes form a tetrahedral shape around the carbon atoms.
4 bonding pairs, 0 lone pairs.
Electron pairs repel each other and thus have to be as far and equally spaced around the carbon as possible.
Bond angle of 109.5 degrees.
As the chain length of an alkane increases, so does the boiling point.
The more electrons you have, and the more distance over which they can move, the bigger the possible temporary dipoles and therefore the bigger the london dispersion forces.
As branching of an alkane increases, the boiling point deceases.
Long thin molecules lie closer together and have more surface contact, making dispersion forces stronger.
Alkanes are relatively unreactive.
σ bonds have low polarity and high enthalpy
the C-C and C-H bonds require a lot of energy to break.
1 of 3
Combustion of Alkanes
The more carbon atoms in the Alkane, the more energy released. But the more oxygen needed.
Complete Combustion
Products are CO2 and H2O
Incomplete Combustion
Products are CO/C and H2O.
Happens when there is a lack of oxygen.
CO is deadly as it binds with the blood in place of Oxygen.
2 of 3
Radical Substitution
Conditions: Presence of UV Light to break the CL2.
Comments
No comments have yet been made