4.2.1 - alcohols

• The functional group of an alcohol is -OH (hydroxyl group)
• The general formula of an alcohol is Cn H2n+1 OH
• To name an alcohol:

  use the prefix with the number of carbon atoms in the chain

  put the position number of the functional group

  add -Ol to the ending
• alcohols can be classified into

  primary

  secondary

  tertiary
• An alcohol is primary when:

  carbon bonded to the OH is only bonded to one or no other carbon atoms eg) methanol or ethanol
• An alcohol is secondary when:

  the carbon bonded to the OH is bonded to two other carbon atoms
• An alcohol is tertiary when:

  the carbon bonded to the OH is bonded to three other carbon atoms
• the equation for the combustion of ethanol is:

  C2H5OH + 3O2 ——> 2CO2 + 3H2O
• An aldehyde is formed when you partially oxidise a primary alcohol
• The functional group of an aldehyde is C=O
• The conditions needed to partially oxidise a primary alcohol are

  dilute sulfuric acid

  potassium dichromate (VI)

  gentle heating and distill product as its produced
• The equation for the partial oxidation of ethanol is:

  CH3CH2OH + [O] ——> CH3CHO + H2O
• When you fully oxidise a primary alcohol a carboxylic acid is formed
• The functional group of a carboxylic acid is -COOH
• The conditions needed to fully oxidise a primary alcohol are:

  concentrated sulfuric acid

  potassium dichromate (VI)

  reflux

  strong heating
• The full oxidation of ethanol is:

  CH3CH2OH + 2[O] ——> CH3COOH + H2O
• A ketone is formed if you oxidise a secondary alcohol
• The functional group of a ketone is C=O
• The conditions needed for oxidation of a secondary alcohol are:

  concentrated sulfuric acid

  potassium dichromate (VI)

  strong heating

  reflux
• The equation for the oxidation of propan-2-Ol is:

  CH3CH(OH)CH3 + [O] ——> CH3COCH3 + H2O
• It is not possible to oxidise a tertiary alcohol
• The general formula of an aldehyde is CnH2nO
• When we write the structural formula of an aldehyde we always write the functional group as CHO
• When the carbonyl group is bonded to one carbon and one hydrogen or two hydrogens it is an aldehyde
• When the carbonyl group is bonded to two carbons it is a ketone
• Aldehydes do not need position numbers however ketones do
• When naming ketones, the prefix comes first for the number of carbon atoms, followed by the position number of the carbonyl group, and then the suffix - one
• when a carbonyl group is attached to a hydroxyl group and a hydrogen it is a carboxylic acid
• The general formula for carboxylic acids is CnH2n+1COOH
• The functional group for esters is -COO
• esters are formed from a reaction between an alcohol and a carboxylic acid
• When esters are formed the OH group is lost from the carboxylic acid and the H is lost from the alcohol
• When esters are named, the alcohol forms the first part of the name

  eg) ,methanol —> methyl
• When esters are named, the carboxylic acid forms the second part of the name

  eg) ethanoic acid —> ethanoate
• The other product formed from esterification along with an ester is a molecule of water
• The general equation for esterification is:

  alcohol + carboxylic acid —> ester + water
• A dehydration reaction is when water is lost to form an organic compound.
• The products of a dehydration reaction of an alcohol are an alkene and water
• The conditions required for dehydration of alcohols is

  concentrated sulfuric acid or phosphoric acid

  170 degrees
• The products of a halide substitution reaction with an alcohol are a haloalkane and water