3.3.5 Alcohols Flashcards
Order of stability carbocation and why
Tertiary>secondary>primary
Tertiary has greater positive inductive effect
Explain why ethanol has a higher boiling point than ethane
Contain hydrogen bonding which is stronger IMF than Van fer Waals
Which type of cracking produces higher proportion of alkenes + conditions
Thermal
High temperatures + pressure
Oxidisation reaction of primary alcohol
Reacts with Potassium dichromate [O] and sulphuric acid to form aldehyde + water (heat + distill off product)
Oxidisation reaction of aldehyde
Reacts with potassium dichromate and sulphuric acid [O] (or Fehling’s solution/Tollen’s reagent) to form carboxylic acid
Oxidisation reaction of secondary alcohol
Reacts with Potassium dichromate [O] and sulphuric acid to form ketone + water (heat or reflux)
Oxidisation reaction of tertiary alcohols and ketones
Not easily oxidised unless you set fire to them
C-C bonds not easily broken
Dehydration of alcohols
Elimination reaction
Alcohols reacted with hot, concentrated H2SO4 at 180°C to produce alkene and water
One reason, other than incomplete combustion or heat transfer to the atmosphere, why the student’s value for the enthalpy of combustion of methanol is different from that in a Data Book.
Evaporation of alcohol
Experiment not done under standard conditions
Heat capacity of copper not taken into account
What reagent is used to convert a carbonyl compound into an alcohol ?
NaNH4
3 conditions necessary for fermentation
Yeast
Anaerobic
Warm
2 advantages of fermentation over hydration of ethene
Renewable
Cheaper equipment
Structure of potassium dichromate
K2Cr2O7
How are alcohols produced industrially
Hydration of alkenes with acid catalyst
Describe how ethanol is produced from ethene
Reaction with steam using phosphoric acid catalyst
Describe how ethanol is produced by fermentation
Glucose from plant material is converted into ethanol and carbon dioxide
Describe how ethanol produced industrially by fermentation is separated by fractional distillation + how it can be used
Liquids with different boiling points in mixture evaporate at different temperatures
Used as biofuel
Explain the term biofuel
Fuels produced from natural products
Often plant biomass containing carbohydrates
Renewable + theoretically carbon neutral
Describe how alkenes can be used to produce addition polymers without using monomers derived from crude oil
Double bonds of the alkene molecules are broken and new single bonds are formed between the carbon atoms of adjacent monomers
