alcohols Flashcards
what is the functional group for alcohols
OH
what is the general formula for alcohols
CnH2n+1 OH
why can alcohols undergo hydrogen bonding
alcohols are polar due to electronegativity of oxygen atom
alcohol molecules hydrogen bond to each other and water molecules
this explains their solubility in water
why is hexanol less soluble than ethanol
longer chain length
so more electrons down the chain
so less soluble
define voltality
how easily something evaporates
why does methanol have a higher boiling point than methane
boiling point in alcohols is higher as alcohols are polar so can undergo hydrogen bonding and van der waals. alkanes only have van der waals so alcohols are less volatile
define primary alcohol
the carbon attached to the OH is only attached to 0 or 1 other carbon atom
they have functional groups at the end of the chain
define secondary alcohol
the carbon attached to the OH is attached to 2 other carbons
they are the molecules with functional group not at end of the chain
define tertiary alcohol
carbon atom is attached to OH is attached to 3 other carbon atoms
they are in molecules in which the functional group is attached to a carbon which also has a branch attached to it
define oxidising agent
causes the other element to be oxidised meaning itself is reduced (reduction = decrease in oxidation number)
what are the 3 ways to define an oxidation
- adding oxygen
- loss of electrons
- increasing oxidation number
list 2 things that can be used as a catalyst in the oxidation of an alcohol to an aldehyde
phosphoric acid
acidified potassium dichromate
how can you control what products are made from the oxidation of an alcohol
to make an aldehyde
= DISTILLATION
aldehyde has a lower boiling point than alcohol so can evaporate it off to prevent further oxidation
(but to make sure you remove all of the aldehyde you need excess alcohol)
to make a carboxylic acid
= REFLUX
the product condenses and then is oxidised
what is the purpose of anti bumping granules
to prevent the formation of big bubbles
when you oxidise secondary alcohols what is formed
a ketone
