Alcohols, Haloalkanes and Analysis Flashcards
(11 cards)
Alcohol
Functional group is OH
General formula is CnH2n+1OH
What is the primary alcohol?
When the alcohol group is attached to a carbon which is attached to one alkyl group
What is a secondary alcohol?
When the OH group is attached to a carbon which is attached to two alkyl groups
What is a tertiary alcohol?
When the OH group is attached to a carbon which is attached to 3 alkyl groups
Describe the solubility of alcohols
All small alcohols are soluble in water due to hydrogen bonding
Longer alcohol molecules become less soluble because the longer carbon chain breaks the potential formation of a hydrogen bond between the alcohol group on the water
Describe the boiling points of alcohols
Boiling points of alcohols are always higher than alkanes
Larger alcohol molecules have higher boiling points
Hydrogen bonding takes place between the alcohol groups. They require a lot of energy to break hence resulting in a high boiling point
London forces get stronger as the carbon chain increases because there are more electrons. They require more energy to overcome as the temporary dipoles are larger so a higher boiling point
Describe the two ways of making ethanol
1) Fermentation from glucose – yeast, 37° C, anaerobic
2) Hydration of ethene- phosphoric acid catalyst, high temp
What type of combustion do alcohols undergo?
Complete combustion
Why are alcohols polar?
The electronegative hydroxy group pulls the electrons in the COH bond away from the carbon atom
Alcohol to haloalkane
Alcohols will react with compounds containing halide ions (such as NaBr) in a substitution reaction
Hydroxyl group is replaced by the halide
Requires an acid such as H2SO4
Alcohol to alkene
Dehydration, elimination of water
Acid catalyst (conc sulphuric or conc phosphoric)
Heat
Often two possible alkene products depending on which side of the hydroxyl group the hydrogen is eliminated from
