alchohols Flashcards
alcohols functional group
-OH
how many alky groups does primary alcohol have
1
how many alkyl groups do secondary alcohols have
2
how many alkyl groups do tertiary alcohols have
3
delta on the oxygen
oxygen- d+
hydrogen- d-
the OH- bond is polar which means that electrons are pulled together with the electronegative oxygen in the covalent bond
why do alcohols interact with water molecules
the d+ charge on the hydrogen bond is attracted to the lone pair of electrons on neighbouring molecules
why are alchols soluble
the dipole interaction allows alchols to dissolve in water
but only shorter chain molecules
what effects the solubility
the longer the carbon chain the more insoluble it is because the carbons is non polar and reduces the interaction the water can be made with the alcohol
what type of bonding does alcohols have
they have hydrogen bonding which is the strongest type of intermolecular force
this means they have higher boiling points then molecules with no hydrogen bonding e.g alkanes
this makes alcohol less volatile
haloalkanes from alcohol
reagent alcohol + halide ion
Conditions acid catalyst H2 SO4
Dehydration of alcohol
alkenes can be made from the dehydration of alcohol eliminating water
Conditions :acid catalyst, e.g. sulphuric acid or phosphoric acid
ethanol = ethane + water
what are alkanes made for?
Polymers for plastic
Elimination reaction
Dehydration of non-primary alcohols can lead to 3 different alkenes
The double bond can be formed either side of the carbon that did have the OH group
Make sure you check if it’s E/Z
combustion of alcohols
alcohols are a few and can be used to generate energy. They ban quickly and form a light blue flame when burnt. They react with oxygen in the air to form carbon dioxide and water the alcohol is being oxidised.
C2H50H +302 = 2 CO2 +3 H2O
oxidation of alcohol
Alcohols can be oxidised to aldehyde ketones and carbonylic acids by as potassium dichloride K2 Cr2 O7
The dichromate will turn from orange Cr2 O7 2- to green chromate ion Cr3+
primary alcohols can be oxidised into?
they can be oxidised into aldehydes and then carboxylic acid
to remove the aldehyde from the oxidising agent we use distillation
To to turn it into carboxylic acid we use reflux and excess oxidising agent because it allows for strong heating without losing volatile
secondary alcohols can be oxidised into?
They can be oxidised into ketones
To turn into a keto use reflux and an oxidising agent
tertiary alcohols can be oxidised into?
NOTHING because it can only oxidise through burning
