4.2.1 - Alcohols Flashcards
Why are alcohols polar?
Electronegative hydroxyl group.
How do they form hydrogen bonds?
Positive charge can attract lone pairs on an oxygen from a neighbouring molecule.
Solubility?
Soluble in water due to hydrogen bonds being formed between -OH and H2O.
What happens with solubility?
Solubility decreases as chain length increases as a larger part of the molecule is made up of non-polar carbon-hydrogen bonds, therefore less attraction for the polar H2O molecules.
Volatility?
Low volatility compared to alkanes of similar size due to hydrogen bonds.
What are primary alcohols oxidised to?
Aldehydes and then to carboxylic acids.
What are secondary alcohols oxidised to?
Ketones only.
What are tertiary alcohols oxidised to?
They are not.
What are primary alcohols oxidised by?
Acidified potassium dichromate.
How are primary alcohols oxidised to aldehydes?
Under distillation.
How are primary alcohols oxidised to carboxylic acids?
Under reflux.
How are secondary alcohols oxidised to ketones?
Under reflux to ensure all reactant is converted to product.
Why can’t tertiary alcohols be oxidised?
Resistant to oxidation and therefore no reaction takes place.
What is the only way to oxidise tertiary alcohols?
Burning them.
In dehydration of alcohols what are the conditions?
H3PO4 catalyst and heat under reflux
