Organic Chemistry 4.29C-4.50C Flashcards
4.29C What is the functional group of alcohols
-OH attached to a hydrocarbon chain
What is the general formula of alcohols
CnH2n+2O
- 31C How can ethanol be oxidised by:
a) burning in air or oxygen
b) microbial oxidisation
c) potassium dichromate (IV) in dilute sulphuric acid
a) Complete combustion of ethanol
C2H6O + 3O2 -> 2CO2 + 3H2O
b) Ethanol reacts with oxygen in the air to form ethanoic acid with microbes as catalysts (enzymes)
C2H6O + O2 -> C2H4O2 + H2O
c) oxidised with potassium dichromate (IV) in dilute sulphuric acid to form carboxylic acids
4.32C How can ethanol be manufactured by hydration
Reacting ethene with steam known as hydration
C2H4 + H2O -> C2H6O (addition reaction)
1 volume of ethene + 0.6 volumes of steam -> 300C, 60-70atm, phosphoric (V) acid catalyst -> gases are cooled and ethanol turns to liquid and unreacted gases recycled
4.32C How can ethanol be manufactured by fermentation
C6H12O6 -> 2C2H6O + 2CO2
glucose -> ethanol + carbon dioxide
Glucose from sugar cane in the absence of air at an optimum temperature of about 30C and using the enzymes in yeast, aerobic respiration would occur in presence of oxygen produced water and carbon dioxide
4.34C what is the carboxylic acids functional group
-COOH
4.36C What do solutions of carboxylic acids react with metals
Forms salts
ethanoic acid + magnesium -> magnesium ethanoate + hydrogen
2CH3COOH + Mg -> (CH3COO)2Mg + H2
ethanoic acid + sodium carbonate -> sodium ethanoate + carbon dioxide + water
4.37C What is vinger
An aqueous containing ethanoic acid
4.38C What are the esters functional group
-COO-
4.44 What is an addition polymer
A large molecule made from small molecules called monomers
How are esters made and what type of reaction is this
A reaction of alcohols with carboxylic acids
Condensation reaction - two molecules react together to make a larger molecule + water
4.39C What is produced when ethanol and ethanoic acid react in the presence of an acid catalyst
Ethyl ethanoate ester and water
In displayed formula remove O-H and H then combine and is normally flipped around
4.41C How do you find out the name of an ester from the alcohol and carboxylic acid
The double bond part is the acid and the number of carbon atoms in a row decipher the ester
4.40C What is the structural formula of ethyl ethanoate
CH3COOCH2CH3
4.42C What are esters used for and properties
Uses:
- Perfume
- Food flavourings
Properties
- Distinctive smell
- Volatile
4.43C Describe a practical to prepare a sample of an ester such as ethyl ethanoate
- Put one drop of conc sulfuric acid into a test tube
- Add 10 drops of ethanol to the test tube
- Add 10 drops of conc ethanoic acid to the test tube
- Cover the top with cling film
- Place the test tube into a beaker containing 100cm3 hot water u the kettle at approximately 60-80C and leave for 5-10 mins
- Remove and pour contents into a beaker with 25cm3 sodium carbonate solution and carefully smell the ester (distinctive)
4.47 What are some problems in the disposal of addition polymers
- Non-biodegradable (not broken down by microorganisms in the environment) so cannot be easily disposed of - land fill
- Produce toxic gases when they are burned - incineration
4.48C What happens in condensation polymerisation
A dicarboxylic acid reacts with a diol, produces a polyester and water
Monomers join together with loss of water
4.50C What are characteristics of some polymers
Biopolyesters are biodegradable
