10.2 Flashcards
Do alkanes contain polar bonds?
No (the carbon to hydrogen bonds are non-polar or weakly polar)
Why are alkanes unreactive?
- Strong covalent bonds
- Non-polar bonds
Types of reactions alkanes undergo
- Combustion
- Free-radical substitution
3 steps in a free-radical substitution reaction
- Initiation
- Propagation
- Termination
Free radical (definition)
Highly reactive species with unpaired electrons
Homolytic bond fission (definition)
Bond breaks evenly, each atom takes 1 electron
Alkane functional group
Alkyl group (CH4)
Alkene functional group
Alkenyl (contains C=C double bond)
Alkyne functional group
Alkynyl (contains carbon-carbon triple bond)
Why are alkenes more reactive than alkanes?
The carbon-carbon double bond involves four bonding electrons, making a region of high electron density that is the site of reactivity. Addition reactions can occur here.
Addition reaction (definition)
2 smaller molecules combine to form a larger molecule
Hydrogenation of alkene: conditions
Nickel catalyst
heat (150° C)
high pressure
hydrogen gas (reagent)
