C1.5 Flashcards
What is crude oil
A thick black oil found in some sedimentary rocks. It’s a fossil fuel made form the remains of Dead Sea animals and plants
How did sea animals and plants become crude oil
When they died, they were buried by the sediment. This kept the oxygen away so they didn’t decay, over time, heat and pressure sunned hem into oil or gas
What is crude oil mostly made from
Mostly made from a mixture of different length hydrocarbons. Sometimes has impurities such as sulfur
What are fractions
The separate liquids separated from a mixture using a fractional distillation column
How is crude oil separated
It’s heated so it boils. The different fractions can then be collected at different heights in the fractional distillation columns as they all cool at different temperature. Shorter chains condense at lower temperatures so rise higher up the column than longer chain hydrocarbons
What are gases used for
Vehicle fuel, bottled gas for camping, heating and cooking in homes
What is petrol for
Car fuel
What is kerosene for
Fuel for planes
What is diesel oil for
Fuel for Diesel engines, cars, lorries, Generators, trains
What is fuel oil for
For ships and some power stations, fuel for heating and lubrication
What is bitumen for
Making roads and waterproofing roofs
How does ease of ignition, boiling point and viscosity change with length of hydro carbon chain
Longer it is, harder it is to infighting, higher the boiling point and the thicker and more sticky it is
What kind of reaction is combustion
An oxidation reaction as the fuel reacts with oxygen
How can you test for water
Anyhydrous copper sulphate turns blue
What is the chemical reaction for complete combustion
Fuel + oxygen —> carbon dioxide + water
What is incomplete combustion
Combustion that occurs when there isn’t enough oxygen so carbon and carbon monoxide are produced instead of carbon dioxide
What defines acid rain
Rain with a pH lower than 5.2
What causes acid rain
When hydrocarbon fuels are burnt, the impurities such as sulphur react with the with the oxygen to form sulfur dioxide, this then condenses in the clouds and joins with the water molecules to make sulphuric acid, causing acid rain
Effects of acid rain
Rivers, lakes and soils become more acidic, harming the organisms living there
Damaging trees, killing them
Speeding up the weathering process of buildings made from soft materials such as limestone or marble and increasing the rate of corrosion of metal
What are greenhouse gases and why do they have that name
Gases in the atmosphere such as carbon dioxide, methane and water vapour and they trap heat in the atmosphere like a greenhouse. Without them the mean temperature on earth would be -18
How can carbon dioxide be removed from the air using iron
Iron compounds can be dropped into the see (iron seeding). Iron is important for plant growth and is often in short supply. This iron encourages the growth of microscopic plants that take in the carbon dioxide for photosynthesis, these are then eaten by animals and the carbon becomes part of there shells. When the animals die, there shells will sink to the bottom of the sea, trapping the carbon dioxide for a long time
How can carbon dioxide be removed
Capturing the carbon dioxide released from power stations and using it to make hydrocarbon fuels such as propane and butane
What are biofuels
Fuels made from organisms that are living or recently died such as animal droppings and wood
How can ethanol be produced
Fermenting wheat, sugar cane or sugar beet.
Why is ethanol good
It can be mixed with petrol for car fuel so reduces the need for petrol and petrol consumption, conserving our crude oil supplies
How is biodiesel made and what is it for
Made by reacting vegetable oil with other things. Can be made from rape seed oil, soya beans or used cooking oil. It can be used by diesel cars or as a mixture with diesel oil. So less diesel needed so less crude oil neede
What is a fuel cell
A device that creates energy by reacting oxygen and hydrogen without burning it so the only product is water
What makes a good fuel
How environmentally friendly it is, how much pollution is released
How well it ignites and burns
How much energy is released
How easy it is to move and store
Why is hydrogen a good fuel
Ignites easily Releases lots of energy 141.8MJ/Kg. Easy to transport, can be piped Easy to store, compressed Only product is water
Why isn’t hydrogen widely used
Not easily available
Sourced from gas, separating process releases carbon dioxide
Expensive to make fuel stations able to store and sell hydrogen
How can you test if something is an alkane or an alkane
Bromine can be mixed with the substance. If there is no colour change, stays orange, it’s a fully saturated hydrocarbon, an alkane
If there is an akène, unsaturated hydrocarbon, the solution becomes colourless
WHat happens in cracking
Long alkane are heated to make shorter molecules, at least one alkane and one alkene
Why is there always an Alkene formed in cracking
Hydrogen and carbon atoms must balance before and after the reaction so one of the molecules will have a free Bond on a carbon so it joins with another carbon to make a carbon double bond
What is a polymer
A substance made up of thousands of simple repeating units called monomers
What is polyethene made from
Lots of ethene monôme s
What is the reaction to make polyethene from ethene molecules
n(ethene) — | H H |
| -c-c- |
| H H |n
Uses and properties of poly(ethene)
Flexible, cheap, good insulator. Used for plastic bags, bottles, cling film and electrical wire insulation
Uses and properties of poly(propène)
Flexible, shatterproof, high softening point. Used for buckets and bowls
Uses and properties of poly(chloroethene) PVC
Tough, cheap, long lasting, good insulator. Used for pipes, window frames, insulation for wires
Uses and properties of poly(tetrafluorethene) teflon
Tough, slippery, corrosion resistant, good insulator. Used for non stick frying pans, bearings, skis, containers for corrosive substances, stain proofing carpets and insulation for wires
Chemical formuler for propène monomor
C2H3(CH3)
Chemical formula for chloroethane
C2H3Cl
Chemical formula for tetrafluorlethene
C2F4
Why are plastics bad
Won’t degrade so will stay in landfill sites for a long time. Can be burnout release toxic gases that need to be collected and safely disposed of
