Chapter 12- Alkanes Flashcards
What are the properties of alkanes?
Have a sigma bond.
Has a tetrahedral arrangement with a bond angle of 109.5
Why do alkanes have a tetrahedral shape?
Due to the repulsion of the electron pairs.
How and why does the boiling point of alkanes vary?
The longer the chain length of the alkanes, the higher the boiling points as there are more London forces present so more energy is required to break them.
Branching decreases boiling point as there are less surface points of contact with London forces. The branches also take up a lot of room so many branches cannot be packed together which decrease the intermolecular forces further.
Why do alkanes have low reactivity?
Sigma bonds are strong.
C-C bonds are non-polar.
C-H bonds can be considered to be non-polar.
What are the reactions that involve alkanes?
Combustion and Reaction with halogens.
What are the stages involved when an alkane reacts with a halogen?
Initiation, propagation and termination.
What are the limitations of radical substitution in organic synthesis?
Further substitutions and Substitution at different positions in a carbon chain.
