CIE AS Chemistry (9701) exams from 2022

Revision Notes

3.4.1 Production of Alcohols

Production of Alcohols

  • Alcohols are compounds that contain at least one hydroxy (-OH) group
  • The general formula of alcohols is CnH2n+1OH
  • Alcohols can be prepared by a wide range of chemical reactions

Electrophilic addition of alkenes

  • When hot steam is reacted with an alkene, using concentrated phosphoric(VI) acid (H3PO4)as a catalyst, electrophilic addition takes place to form an alcohol

 

Hydroxy Compounds Electrophilic Addition, downloadable AS & A Level Chemistry revision notes

Electrophilic addition of steam to alkenes to form an alcohol

Oxidation of alkenes

  • Cold, dilute KMnO4 is a mild oxidising agent and oxidises alkenes
  • The C-C double bond is not fully broken and a diol is formed
    • A diol is a compound with two hydroxy, -OH, groups

 

Hydroxy Compounds Oxidation, downloadable AS & A Level Chemistry revision notes

Oxidation of alkenes using cold, dilute KMnO4 to form a diol

Nucleophilic substitution of halogenoalkanes

  • The halide atom in halogenoalkanes can be substituted when heated with aqueous NaOH in a nucleophilic substitution reaction

 

Hydroxy Compounds Nucleophilic Substitution, downloadable AS & A Level Chemistry revision notes

Nucleophilic substitution of halogenoalkanes using NaOH to form an alcohol

Reduction of aldehyde & ketones

  • Aldehydes and ketones can be reduced by reducing agents such as NaBH4 or LiAlH4 
  • Aldehydes are reduced to primary alcohols
    • The carbon attached to the hydroxy group is bonded to one other alkyl group
  • Ketones are reduced to secondary alcohols
    • The carbon attached to the hydroxy group is bonded to two other alkyl groups

 

Hydroxy Compounds Reduction, downloadable AS & A Level Chemistry revision notes

Reduction of aldehydes and ketones to form primary and secondary alcohols

Reduction of carboxylic acids

  • Similarly, carboxylic acids are reduced by NaBH4 or LiAlH4 to primary alcohols
  • Carboxylic acids can also be reduced by H2 using a nickel catalyst and heat

 

Hydroxy Compounds Reduction 2, downloadable AS & A Level Chemistry revision notes

Reduction of carboxylic acids to primary alcohols

Hydrolysis of ester

  • Esters are made by a condensation reaction between an alcohol and a carboxylic acid
  • When an ester is heated with dilute acid or alkali, hydrolysis will take place and the carboxylic acid and alcohol will be reformed

 

Hydroxy Compounds Hydrolysis, downloadable AS & A Level Chemistry revision notes

Hydrolysis of esters to form alcohols

Alcohol production reactions table

Hydroxy Compounds Table 1_Production of Alcohols, downloadable AS & A Level Chemistry revision notes

Exam Tip

The symbol [O] is used to represent oxygen provided by an oxidising agent.

Close

Join Save My Exams

Download all our Revision Notes as PDFs

Try a Free Sample of our revision notes as a printable PDF.

Join Now
Go to Top