Alcohols (P2+P3) Flashcards
Name the mechanism, reagents and conditions from alkene to alcohol.
Direct hydration
reagents: steam
conditions and catalyst: conc H3PO4
2 advantages of hydration of ethene
high rate of reaction
high purity product made
2 disadvantages of hydration of ethene
high temp and pressure needed; increased cost
crude oil is non renewable
2 advantages of fermentation
uses renewable resources
low cost
2 disadvantages of fermentation
slow rate of reaction
less efficient
What is biofuel?
a fuel produced from biomass (renewable plant material)
2 advantages of biofuel
carbon neutral
comes from renewable raw materials
2 disadvantages of biofuel
food prices rise as crops used for biofuels
the supply of biofuels is dependent on crop harvest so is less reliable.
Name of mechanism, reagents and conditions from alcohols to alkenes.
elimination (dehydration)
reagent: H2SO4
conditions: hot, conc
Oxidation of primary alcohol under distillation forms an…
under what reagent and conditions
observation?
Aldehyde
reagent: acidified potassium dichromate
conditions: distillation
observation: orange to green
Ehanol oxidised to ethanal equation
CH3CH2OH + [O] –> CH3CHO +H2O
Oxidation of primary alcohol under reflux forms a…
under what reagent and conditions
observation?
Carboxylic acid
reagent: acidified potassium dichromate
conditions: reflux
observation: orange to green
Ethanol oxidised to ethanoic acid equation
CH3CH2OH + 2[O] –> CH3COOH +H2O
Ethanal oxidised into ethanoic acid equation
CH3CHO + [O] –> CH3COOH
NO WATER MADE
Why is reflux used to oxidise an alcohol into a carboxylic acid?
reflux doesn’t allow any reactant vapour to escape.
Oxidation of secondary alcohol forms a…
under what regent and conditions
observation?
Ketone
reagent: acidified potassium dichromate
conditions: distillation or reflux
observation: orange to green
Propan-2-ol oxidised to propanone equation
CH3CH(OH)CH3 + [O] –> CH3COCH3 + H2O
Test for aldehydes or ketones (silver mirror)
Tollens reagent
warm gently
Aldehyde: Silver mirror forms
Ketone: NVC
Test for aldehydes and ketones (Fehling’s test)
Fehling’s solution
warm gently
Aldehyde: blue to brick red ppt
Ketone: NVC
Test for carboxylic acid
Sodium carbonate
effervescence
