Organic II Flashcards
What is an alcohol?
organic molecule, contains an -O-H functional group (hydroxyl)
Molecular formula for ethanol?
C₂H₆O
Molecular formula for methanol?
CH₄O
Molecular formula for propanol?
C₃H₈O
Molecular formula for butanol?
C₄H₁₀O
What is an isomer of propan-1-ol?
Propan-2-ol
What methods can be used to manufacture ethanol?
Hydration of ethene
fermentation of glucose
Write the chemical equation for the hydration of ethene
C₂H₄ + H₂O -> C₂H₅OH
Write the chemical equation for the fermentation of glucose
C₆H₁₂O₆ -> 2C₂H₅OH + 2CO₂
What conditions are needed for the hydration of ethene?
300ºC
65 atm pressure
phosphoric acid catalyst
What conditions are needed for the fermentation of glucose?
30ºC
yeast
anaerobic
What are the advantages for hydration of ethene?
One product produced (ethanol)
continuous process
What are the disadvantages for hydration of ethene?
requires lots of energy
non renewable raw material
What are the advantages for the fermentation of glucose?
renewable raw material
not energy intensive
What are the disadvantages for the fermentation of glucose?
impure ethanol (produces CO₂ aswel)
batch process
What common name is given to a solution of ethanoic acid?
vinegar
What can ethanol turn into?
ethanoic acid
Write an equation for the complete combustion of ethanol
C₂H₅OH + 3O₂ -> 2CO₂ + H₂O
Why is a blue flame needed for the complete combustion of ethanol?
alcohols contain oxygen therefore more complete combustion
What methods can be used to produce ethanoic acid?
microbial oxidation
chemical oxidation
What is the microbial oxidation of ethanol?
micro-organisms (bacteria) use oxygen in the air to oxides ethanol
Write the chemical equation for microbial oxidation of ethanol
C₂H₅OH + 2[o] -> CH₃COOH + H₂O
Write the chemical equation for chemical oxidation of ethanol
C₂H₅OH + 2[o] -> CH₃COOH + H₂O
What is the oxidising agent used in the chemical oxidation of ethanol?
potassium dichromate
Describe the chemical oxidation of ethanol
add sulphuric acid to ethanol
add potassium dichromate
heat in water bath (to speed up rate of reaction)
What is the colour change involved in the chemical oxidation of ethanol?
orange -> green
What is a carboxylic acid?
weak acids
will react less violently / quickly than other acids
Give examples of carboxylic acids
methanoic acid
ethanoic acid
propanoic acid
butanoic acid
What is the structural formula for methanoic acid?
HCOOH
What is the structural formula for ethanoic acid?
CH₃COOH
What is the structural formula for propanoic acid?
CH₃CH₂COOH
What is the structural formula for butanoic acid?
CH₃CH₂CH₂COOH
ethanoic acid + sodium hydroxide -> ?
water + sodium ethanoate
ethanoic acid + sodium oxide -> ?
water + sodium ethanoate
ethanoic acid + sodium -> ?
hydrogen + sodium ethanoate
ethanoic acid + sodium carbonate -> ?
carbon dioxide + water + sodium ethanoate
describe the differences between the reactions of hydrochloric acid and ethanoic acid
ethanoic acid produces less vigorous reaction
both turn limewater cloudy
What is observed when magnesium is placed in propanoic acid?
effervescence
Mg dissapears
Name the products formed when magnesium is placed in propanoic acid
Magnesium propanoate
What is an ester?
family of organic molecules which form when a carboxylic acid and an alcohol join together by losing an H₂O molecule
ethanoic acid + ethanol -> ?
ethyl ethanoate + water
methanoic acid + propanol -> ?
propyl methanoate + water
Carboxylic acid + alcohol -> ?
ester + water
alcohol acid e.g. ethyl ethanoate
How do you make esters?
mix carboxylic acid and alcohol together
add a few drops of concentrated sulphuric acid (catalyst)
warm gently
How do you smell esters?
tip into sodium carbonate solution (neutralises excess acid)
cautiously smell
smells fruity
Working Backwards:
Pentyl ethanoate -> ?
ethanoic acid + pentanol
What is a polymer?
A long chain molecule made of repeating units
What is a monomer?
A small molecule used to make a polymer
Name the polymer that has:
two C
two H
Chlorine
Fluorine
poly(chlorofluoroethene)
Name the polymer that has:
two C
three H
CH₃
poly(propene)
What is a polyester?
a polymer made from lots of molecules (monomers) joined together by ester groups
What does a polyester produce?
2nH₂O
What does biopolyester mean?
biodegradable