Organic Chemistry Flashcards
What is crude oil?
Remains of ancient plankton buried in mud A mixture of hydrocarbons
Why is crude oil described as a finite resource?
It’s non-renewable (will run out)
What is a hydrocarbon?
A compound made of hydrogen and carbon only
What is the general formula for alkanes?
CnH2n+2
Name this molecule
Methane
Name this molecule
Ethane
Name this molecule
propane
Name this molecule
butane
What is crude oil used for?
fuels
feedstock for chemicals
polymers
Explain how fractional distillation separates crude oil
Crude oil heated to 350oc
it vaporises
the top of the column is cooler and the bottom is hotter
small alkanes condense at the top of the column
large alkanes condense at the bottom of the column
Explain why longer alkanes have higher boiling points
They have stronger forces between the molecules
which require more energy to overcome
Explain why viscocity of the alkanes increases as the length of the chain increases
Longer molecules have stronger forces between the molecules
How does flammability of alkanes change with chain length?
the larger the chain length the less flammable the hydrocarbon
Name the two products of complete combustion of hydrocarbons
carbon dioxide and water
Describe how longer alkanes are cracked
Heated until vaporised
passed over a hot catalyst
Describe the test for alkenes
Bromine water
turns from orange to colourless
Name a use of alkenes
Produce polymers
Why are alkenes described as unsaturated?
They contain a C=C double bond
Why are alkanes described as saturated?
They contain only C-C single bonds
What is the general formula for alkenes?
CnH2n
Name this molecule
Ethene
Name this molecule
Describe the conditions for the hydrogenation of ethene
60oc
Nickel catalyst
State the product of the reaction of ethene with hydrogen
ethane
Describe the conditions for the hydration of ethene (adding water)
300oc (steam)
acid catalyst
Draw the product of the reaction of ethene with steam
ethanol
Draw the product of the reaction of ethene with chlorine
State alcohol’s functional group
-OH
Name this molecule
Ethanol
Name this molecule
propanol
Describe how sodium reacts with ethanol
Sinks
bubbles slowly
Write an equation for the combustion of ethanol
C2H5OH + 3O2 –> 2CO2 + 3H2O
Describe what happens when alcohols are left in air
They oxidise
to form carboxylic acids
name this molecule
propanoic acid
name this molecule
ethanoic acid
name this molecule
ethyl ethanoate
State the functional group of carboxylic acids
-COOH
Explain why carboxylic acids are described as weak acids
They only partially ionise
releasing few H+ ions
Describe how ethyl ethanoate is formed
Reacting ethanol and ethanoic acid
with an acid catalyst
Finish this equation
What is a polymer?
A large molecule
formed from many monomers
What is condensation polymerisation?
When two small molecules join releasing water
What two types of monomer form a polyester?
A diol
a dicarboxylic acid
Describe differences between condensation and addition polymerisation
- Condensation produces a polymer and water
- Addition produces only polymer
- Addition has one monomer, an alkene
- Condensation has two polymers (a diol and dicarboxylic acid)
- addition polymers produce a carbon chain
- condensation polymers have an ester link
