Topic 5 - Fuels Flashcards
what is crude oil?
crude oil is a mixture of hydrocarbons
what are hydrocarbons?
hydrocarbons are compounds containing only hydrogen and carbon
what is the name of the method used to separate hydrocarbons/ crude oil?
fractional distillation
where does fractional distillation of crude oil take place?
in a fractionating column
as the hydrocarbons get larger (the greater number of carbon atoms in a molecule) they become…
- more viscous
- less flammable
- less volatile
- have a higher boiling point
what are refinery gases?
e.g. liquified petroleum gas, propane and butane for bottled gases
what is gasoline (petrol) used for?
fuel for cars
what is kerosene (paraffin) used for?
fuel for jet aircrafts
what is diesel oil (gas oil) used for?
fuel for cars and large vehicles
what is fuel oil used for?
generating electricity and in marine diesel engines
what is bitumen used for?
to make roads
is bitumen a long or short chain hydrocarbon?
long-chain hydrocarbon
is petrol a long or short chain hydrocarbon?
short-chain hydrocarbon
what is a fuel?
a fuel is a substance that releases useful amounts of energy when burned
when a fuel burns, it reacts with ________ in the air.
what is the missing word?
oxygen
what is complete combustion?
complete combustion is when a hydrocarbon burns with substantial amounts of oxygen, meaning carbon dioxide and water are produced, and energy is released.
what is incomplete combustion?
incomplete combustion is when a hydrocarbon burns with insufficient amounts of oxygen, meaning carbon monoxide and water are produced.
what is (extreme) incomplete combustion?
(extreme) incomplete combustion is when a hydrocarbon burns with very little oxygen, and therefore carbon, a solid, is produced as well as water.
what is carbon monoxide?
carbon monoxide is a toxic, colourless and odourless gas that combines irreversibly with the haemoglobin in red blood cells, reducing their oxygen-carrying ability, which eventually results in death by lack of oxygen
what are some of the problems associated with acid rain?
- damage to:
- plants
- animals
- buildings
- metals - increase in acidity levels of lakes and rivers, which can be harmful to organisms living in them
what is global warming?
global warming is the gradual increase in temperature of the Earth’s atmosphere
why is the surface of the Earth warmer than it would be without the gases: -carbon dioxide -methane -water vapour in the atmosphere?
because these gases in the atmosphere absorb heat and radiate it back down to Earth
what is iron-seeding?
iron-seeding is a process of removing carbon dioxide from the atmosphere:
- iron dust is added to oceans
- this enhances the growth of plankton, which takes in carbon dioxide
- this therefore reduces the amount of carbon dioxide in the atmosphere
how can chemists convert carbon dioxide into a simple hydrocarbon?
by using a catalyst
what is the name of substances that are becoming an attractive alternative to fossil fuels?
biofuels
what are biofuels based on?
sustainable resources such as wood and alcohol from plants
what is ethanol?
ethanol is an alcohol produced by the fermentation of sugar beet and sugar cane.
what is ethanol used for?
- as a fuel in its purest form
- added to petrol to reduce the need for petrol and to improve vehicle emissions
what is a disadvantage to using ethanol?
large areas of fertile land are needed to grow the crops (sugar beet and sugar cane)
what is a fuel cell?
a fuel cell is a way of producing and harnessing energy from a chemical reaction
what is the cleanest of all the fuels, and why?
hydrogen, because it only produces water in a fuel cell
what are the main factors of a good fuel?
- safe to transport/ does not catch alight easily
- easy to transport and store
- good provider of heat energy
- clean fuel that produces little or no toxic or polluting products
how can the amount of energy released by the combustion of different fuels be compared?
by measuring the temperature rise of a fixed volume of water as it is heated by a known amount of a certain fuel
What are the advantages and disadvantages of using biogas like bio methane as an alternative to fossil fuels?
Advantages - Renewable, sustainable Easy to replace crops use to produce biogas quickly Carbon neutral Clean fuel with few pollutants released Cheap
Disadvantages -
Less land to grow food for people who need it
Large storage space need to store the gas
Transport
What are the advantages and disadvantages of using bioethanol?
Advantages -
Less crude oil use
Carbon neutral
Clean fuel few pollutants released
Disadvantages -
Less land to grow food
Requires suitable climate
Distillation needed after produced
Advantages and disadvantages of hydrogen fuel cells?
Advantages-
No pollutants
No recharging required
Very efficient, not a lot of energy wasted
Disadvantages - Storage space needed explosive gas Energy needed to use electrolysis which requires energy Expensive (electrolysis)
How do you measure the energy content in fuels?
Colorimetric method
Describe the experiment in which you can measure the energy content of fuels?
Weigh fuel Fixed volume of water in beaker Set up draft shield Light fuel and heat water by 10 degrees Re-weigh fuel Calculate mass difference Repeat with another fuel (replace water)
What is cracking?
A thermal decomposition react that breaks down long chain alkanes into smaller, more useful alkanes and alkenes
What does cracking require in order to break down a hydrocarbon?
Heat & a catalyst
Examples of natural polymers?
Starch (formed from glucose) and protein (formed from amino acids)
What is a monomer?
A monomer is a short-chain unsaturated hydrocarbon molecule.
What are the properties of poly(ethene) and what are its uses?
Properties-
Good chemical resistance, light, flexible
Uses -
Food coverings, plastic bags, hose and water pipes
What are the properties and uses of poly(propene)?
Properties-
Flexible, tough, good chemical resistance
Uses -
Ropes, chairs, stationary, crates
What are the properties and uses of poly(chloroethene) PVC?
Properties -
Water-resistant, flexible or rigid
Uses -
Clothing, double-glazed window frames, electrical components, pipes
what are the uses and properties of poly(tetraflouroethene) , PTFE?
Properties -
Water and flame resistant, flexible, durable, unreactive
Uses -
non-stick cookware coating, waterproof coatings
Why are plastics/polymers hard to dispose of?
- non-biodegradable so remain in landfill sites taking up space
- burning them releases pollutants/toxic gases
- only some plastics can be recycled
What properties make a good fuel?
Ease of ignition
Energy produced
Waste gases pollutants given off
Storage and transport easy?
What environmental effect does sulfur dioxide have?
Dissolves easily in water, contributing to acid rain which causes damage to lakes, rivers, houses, farms, buildings
Why are people concerned with the level of carbon dioxide in the atmosphere?
Carbon dioxide is a greenhouse gas, meaning that it traps heat in the atmosphere and radiates it back down to earth.
