2.5 Crude Oil, Fuels and Organic Chemistry Flashcards
How is crude oil formed?
The remains of dead sea organisms sink to the bottom of the sea, over time the dirt builds up on top and then they decay anaerobically causing the shells of the dead organisms to form crude oil.
The crude oil rises and is trapped underneath rocks which we drill through to get to it.
What is crude oil a mixture of?
Hydrocarbons (hydrogen and carbon only)
What does the larger the hydrocarbon result in? Why?
The less volatile(difficult to get into a gas)
High melting and boiling point
More viscous
Less flammable
Because stronger intermolecular bonds
What is the fractional distillation process?
- Crude oil is a complex mixture of hydrocarbons
- Crude oil is heated to a vapour then put in a fractional distillation column
- Column is the hottest at the bottom and cools towards the top
- Hydrocarbons make their way up the column and condense at diff temp and collected on plates as fractions.
- Large hydrocarbons condense at the bottom and small condense higher up the column
What are the prefixes for up to five carbon atoms?
- Meth-
- Eth-
- Prop-
- But-
- Pent-
Are alkanes saturated or unsaturated? Do they have a double bond?
Saturated
No
What is the general alkane formula?
CnH2n+2
How do you name alkane isomers?
Number all the carbons
Put the number of the extra carbon at the beginning of the name (has to be lowest it can be
CH3
I
e.g C-C-C-C
2-Methyl butane
Are alkenes saturated or unsaturated? Do they have a double bond?
Unsaturated
Yes, one double bond
What is the general formula for alkenes?
CnH2n
How do you name alkene isomers?
Same of alkanes but the double bond must be the lowest.
e.g C-C=C-C-C
I
CH3
2-Methyl Pent-2-ene
What is isomerism?
Same chemical formula, different chemical structure
What is cracking?
to produce smaller and more useful
hydrocarbon molecules, including monomers (alkenes) which can be used to
make plastics
Answer : C10H22 -> C2H4 + C5H12 + ?
C3H6
What are addition reactions?
Addition of two atoms across the C=C bond in an unsaturated compound thus forming a saturated compound.
What is and identifying test for an alkene and alkane and what do they show?
Addition of bromine water
Alkenes decolourise
Alkanes have no change/stay brown
Answer : H H
I I
C=C + Br-Br ->
I I
H H
H H
I I
H - C-C - H
I I
Br Br
What are polymers and how are they formed?
Use of chemicals from crude oil to make plastic
Formed when many smaller molecules join together (monomers)
What are the key features of a monomer?
- double bond (so an alkene)
- no line through the bracket
- “n” before the bracket
What are the key features of a polymer?
- single bonds
- lines through bracket
- “n” after bracket
What is addition polymerisation?
When monomers double bond open up and join to neighbouring molecules making a very long singly bonded chain
What are the properties and uses of Polytherene?
Uses: drinking cups and bottles
Props: Doesn’t absorb water
What are the properties and uses of Polyvinylchloride (PVC)?
Uses: window frames and drain pipes
Props: corrosion resistant, waterproof, heat resistant
What are the properties and uses of Polystyrene?
uses: packaging, model kits, insulation
props: light, impact resistant, traps heat
What are the properties and uses of Polytetraflyorathene (PTFE)?
uses: teflon, non-stick pans
props: high melting point, non-stick
Explain why plastics have replaced traditional materials for everyday things?
Plastics are cheaper, easier to produce, reused and recylced, wide variation in properties, do not biodegrade
What are the three disposal methods and their pros and cons?
- landfill, removed plastic, destroys habitats, plastic doesn’t biodegrade
- burning, gets rid of plastic, no landfill needed, produces toxic gases
- recycling, less pollution, saves land, nontoxic, plastic weakens after many uses
What is the combustion equation?
Fuel + Oxygen -> Carbon Dioxide + Water
What are the three factors in a fire triangle needed for combustion to happen?
Heat - Water eliminates
Fuel - Firebreak eliminates
Oxygen - Remove oxygen
Why shouldn’t you use water in an oil fire?
Because the water is denser than oil and sinks making the oil splash and spit spreading the fire
What is the combustion reaction of hydrogen?
2H2 + O2 -> 2H2O
What are the advantages of using hydrogen as fuel?
-versatile
-doesn’t produce CO2, only water
-releases lots of energy
-renewable
-very abundant
What are the disadvantages?
-dangerous
-produced by electrolysis
-storage is expensive and heavy
-extremely flammable
-volatile (low bp)
-lots of electricity needed (expensive)
What is the word equation for fermentation?
glucose (plus yeast) -> ethanol + carbon dioxide
What is the symbol equation for fermentation?
C6H12O6 (yeast) -> 2C2H5OH + 2CO2
How can ethanol be removed using distillation?
mixture isheated until ethanol boils, ethanol gas then condenses to form pure ethanol liquid
What are some social impacts of drinking?
people get drunk, relaxing for people, can lead to violence/damage/ addictions
What are some economic impacts of drinking?
earns tax money, repairs,medical costs, policing costs
What are the two methods of producing ethanol?
Fermentation and Addition
What are the advantages of fermentation?
low temp so less energy needed, sugar is a sustainable course, low pressure so cheaper
What are the disadvantages of fermentation?
produces CO2, waste product, stop start production is expensive, sugar needs time to grow
What are the advantages of addition to make ethanol?
continuous production, no CO2 produced
What are the disadvantages of addition to make ethanol?
high temp, high pressure, crude oil needed so not renewable
What is the general formula for an alcohol?
CnH2n+1OH
How can you test for alcohols?
Acidified potassium dichromate
What colour will alcohols show when acidified potassium dichromate is added?
orange-green
Name this alcohol isomer:
H H H OH
l l l l
C C C C
Butan-1-ol
What is the chemical formula for ethanoic acid?
CH3COOH
