Studied by 12 peoplewhat are alcohols?
molecules containing the hydroxyl (-OH) group
what are primary alcohols?
the carbon bonded to the hydroxyl group is bonded to one other carbon
what are secondary alcohols?
the carbon bonded to the hydroxyl group is bonded to two other carbons
what are tertiary alcohols?
the carbon bonded to the hydroxyl group is bonded to three other carbons
what are diols?
molecules with 2 hydroxyl groups
why are alcohols less volatile than alkanes + alkenes?
as chain length increases, melting point and boiling point increases, so volatility decreases
why does solubility decrease as chain length increases?
as chain length increases, the non-polar region has a greater influence on solubility than the polar, OH group, so solubility decreases
what is meant by oxidation, in terms of carbon?
a molecule is oxidised when carbon forms a bond with a more electronegative element
what is meant by reduction, in terms of carbon?
a molecule is reduced when carbon forms a bond with a less electronegative element
what are primary alcohols oxidised to?
primary alcohols are oxidised to aldehydes, which are further oxidised to carboxylic acids
what are secondary alcohols oxidised to?
secondary alcohols are oxidised to ketones
why are tertiary alcohols oxidised to?
tertiary alcohols cannot be oxidised
what oxidising agent is used to oxidise alcohols?
[O] - acidified potassium dichromate ions
how can alcohols be tested for?
primary + secondary alcohols: acidified dichromate ions turn the solution from orange to green
tertiary alcohols: solution stays orange
by what process are aldehydes prepared?
distillation
by what process are ketones and carboxylic acids prepared?
reflux
what do alcohols produce (+ conditions) in elimination reactions with water?
alkenes and water
conditions: concentrated acid catalyst, heat
what do alcohols produce (+ conditions) in substitution reactions with sodium halide salts?
haloalkanes, water + salt
conditions: acid catalyst
what test can distinguish primary and secondary alcohols?
add tollens’ reagent and heat.
if silver mirror produced, aldehyde, therefore primary alcohol
if no silver mirror produced, ketone, therefore secondary alcohol
how can fehling’s solution distinguish between primary and secondary alcohols?
fehling’s solution turns red in primary alcohols, but stays blue in secondary alcohols
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