AlcoholsEdexcel A-Level Chemistry: Mind map

Exam questions on Alcohols

1. A technician is given four structural isomers of molecular formula C₄H₁₀O: butan-1-ol, butan-2-ol, 2-methylpropan-1-ol and 2-methylpropan-2-ol. She will warm each with acidified potassium dichromate(VI) solution and compare the results.
   Explain why 2-methylpropan-2-ol does not change the colour of acidified potassium dichromate(VI) solution when warmed.2 marks
2. A chemist converts propan-1-ol into three different halogenoalkanes: 1-chloropropane, 1-bromopropane and 1-iodopropane. A different reagent or reagent mixture is needed for each halogen.
   Write two equations to show how potassium bromide and 50% concentrated sulfuric acid convert propan-1-ol into 1-bromopropane. The first equation shows the formation of the reactive halogenating species.2 marks
3. A student carries out Core Practical 5 on the oxidation of ethanol using acidified potassium dichromate(VI). In one experiment she wants to collect ethanal; in a second experiment she wants to make ethanoic acid.
   Describe how she should carry out the experiment to collect ethanal, and explain why this method prevents further oxidation.3 marks