Paper 2- Alcohols Flashcards
(16 cards)
Why do alcohols have higher boiling points than alkanes?
Alcohols contain hydrogen bonding
Why are alcohols soluble in water?
O-H bond is polar
Why do alcohols get less soluble as chain length increases?
Greater proportion of the molecule that isn’t polar
Why are the hydrogen bonds weaker in tertiary alcohols than in primary alcohols?
Other alkyl groups attached to O-H bond get in the way of other molecules hydrogen bonding with it (steric hinderance)
What conditions are used when forming alcohol from ethene?
6500kPa
570K
Concentrated phosphoric acid catalyst
What conditions are used to make alcohol by fermentation?
30-40 celsius
Microorganism catalyst to supply enzymes
What is a biofuel?
A fuel derived from renewable biological sources
Define oxidation in terms of hydrogen
Loss of hydrogen
Define reduction in terms of hydrogen
Gain of hydrogen
What is observed when adding acidified potassium dichromate to primary or secondary alcohols?
Orange to green
What can primary alcohols be oxidised into?
Aldehyde
Carboxylic acid
What can secondary alcohols be oxidised into?
Ketones
Why can’t tertiary alcohols be oxidised?
There is no hydrogen attached to the carbon for the oxygen to remove
What reagent and conditions are needed to selectively oxidise a primary alcohol into an aldehyde?
Reagent: Acidified potassium dichromate
Conditions: Distillation immediately
What reagent and conditions are needed to selectively oxidise a primary alcohol into a carboxylic acid?
Reagent: Acidified potassium dichromate
Conditions: Reflux
What is a dehydration reaction?
The elimination of water from a compound
