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What is the functional group of alcohols?
-OH
What is the general formula of alcohols?
CnH2n+1OH
What are the properties of alcohols?
Flammable - can undergo complete combustion Soluble - solution will have a neutral PH Oxidised to form Carboxylic acid with (potassium dichromate (VI) and heat)
What happens when we oxidise an alcohol?
A carboxylic acid is formed Potassium Dichromate (VI) is required and heat
What is the colour change of oxidation of alcohol using potassium dichromate (VI)
Potassium Dichromate (VI) turns from orange to green
What are the 3 ways alcohol can be oxidised?
Using an oxidising agent (potassium dichromate VI) in dilute sulfuric acid Microbial oxidation - Carboxylic acid is produced as a by product as they use alcohol as their energy source Combustion
What are the uses of alcohols?
Used as fuel As solvents in industry
State two ways to produce ethanol? Conditions
Ethen + steam: - Addition reaction Phosphoric acid catalysts 300 degrees 60-70 atm pressure Fermentation of glucose by yeast: - Anaerobic respiration Requires yeast 30-40 degrees Anaerobic conditions
Chemical equation for production of ethanol through hydration?
C2H4 + H20 -> C2H5OH
Chemical equation for production of ethanol through fermnetation?
C6H12O6 -> C2H5OH + CO2
Advantages and disadvantages of production of ethanol through hydration?
Pros: No waste products - efficient Cheap process Cons: Ethene is made from crude oil which is a finite resource
Advantages and disadvantages of production of ethanol through fermentation?
Pros: Glucose is a renewable resource Yeast are easy to grow Cons: Process is relatively slow Ethanol is weak and not pure so has to be distilled and purified
Functional group of Carboxylic acid?
-COOH
Are carboxylic acids strong or weak acids? What does that mean?
Weak acids - they don’t fully ionise. All the carboxylic acids don’t all release their hydrogen ions
What happens when carboxylic acids react with metal carbonates?
Salt (magnesium ethanoate) + Water + Carbon Dioxide
What happens when carboxylic acids react with metals?
Salt + Hydrogen
How are carboxylic acids made?
By oxidising an alcohol
What are carboxylic acids used for?
Ethanoic acid is dissolved in water to make vinegar: This is used for flavourings and preserving foods
What is the functional group of an ester? Where is it found?
-COO- functional group found in the middle of the molecule
Alcohol + Carboxylic acid (with an acid catalyst) ->
Ester + water
How do we name an ester?
Alcohol forms the first part and acid forms the second part eg. Methyl Propanoate
Characteristics of esters?
Pleasant smells (Sweet or fruity) Volatile (Evaporate easily)
How do we make an ester? Method Use ethyl ethanoate?
Ethanoic acid + Ethanol • Add a few drops of concentrated sulfuric acid to a boiling tube using a dropping pipette • Add 10 drops of ethanoic acid • Add an equal volume of ethanol • Place boiling tube, in a beaker of water, on a tripod. • Heat till the water boils and then allow to cool • Once it’s cool pour the mixture into a test tube of sodium carbonate solution and mix • Layer of ester should form on the top (sweet smell)
Why does water form when an alcohol and carboxylic acid react?
As the carboxylic acid loses the -OH from its -COOH functional group And the alcohol lose the H from its -OH functional group These combine to form H2O