Topic 8 - Fuels and Earth Science Flashcards
What is crude oil?
Crude oil is a mixture of different compounds, most of which are hydrocarbons
is crude oil finite or renewable?
Finite
How was crude oil made?
It is formed from the remains of dead organisms, especially plankton that were covered by mud and sand and buried in the earth. Over millions of years the heat and pressure compressed the remains and chemically changed them into crude oil
What are the 3 fossil fuels?
Crude oil, natural gas and coal
How does fractional distillation work?
Crude oil is a mixture of compounds with different boiling points. We heat the crude oil to a very high temperature so that all the compounds evaporate and turn into gas that rises up the column. As the gas rises it cools because the top of the column isn’t as hot as the bottom. The gases will condense and collect in trays and drain out at different heights of the column depending on their boiling point. The longer chain hydrocarbons condense at the bottom because they have higher boiling points and the shorter chain hydrocarbons condense at the top because they have lower boiling points
What are the main products of crude oil from fractional distillation from highest to lowest boiling point?
Bitumen, Heavy fuel oil, diesel, kerosene, petrol and liquefied petroleum gas
What are all the products of crude oil that are used for fuel from fractional distillation?
heavy fuel oil (ships), diesel (heavy-duty vehicles), Kerosene (aeroplanes), petrol (cars), and liquefied petroleum gas (cookers)
Is the top of the fractionating column hotter or colder than the bottom?
The top is colder than the bottom
What is a feedstock?
A raw material used to provide reactants for an industrial reaction
What is a petrochemical?
A substance made from crude oil via chemical reactions
What are the different hydrocarbons in crude oil, feedstocks or petrochemicals?
Feedstocks
What are the products made from the different hydrocarbons in crude oil, feedstocks or petrochemicals?
Petrochemicals
What is an isomer?
molecules that have the same molecular formula but different structural formulas; they are made from the same atoms but the atoms are arranged differently
What is organic chemistry about?
Molecules that contain carbon
What is a hydrocarbon?
A compound that contains only the elements hydrogen and carbon
What are alkanes?
A homologous series of molecules that contain only hydrogen and carbon atoms and have only single bonds
What is homologous series?
A homologous series is a group of organic compounds that have similar chemical properties due to them having the same general formula
What are the formulae for methane, butane, ethane and propane?
Methane: CH4
Butane: C4H10
Ethane: C2H6
Propane: C3H8
What is the general formula of alkanes?
CnH2n+2
What type of bonds are present in alkanes?
Covalent bonds
What is a word to describe hydrocarbons with single bonds?
Saturated
What is the formula for complete combustion of a hydrocarbon?
Hydrocarbon + Oxygen –> Carbon dioxide + Water
What are 2 negative effects of soot and how is soot produced?
Soot is produced from incomplete combustion of hydrocarbons that forms clouds of smog which reflect light back to space and causes respiratory problems as the particles damage our lungs
What is the formula for the incomplete combustion of hydrocarbons?
Hydrocarbon + Oxygen –> Carbon Monoxide + Particulates (soot)
Why is carbon monoxide harmful to humans>
When we breathe in carbon monoxide it diffuses into our bloodstream and binds to our haemoglobin, reducing the amount of oxygen our haemoglobin can carry. This means that less oxygen is transported to our tissues which can cause fainting, comas and death
When burning fossil fuels how is sulfur dioxide produced?
Sulfur is an impurity in some fossil fuels and is oxidised when they are combusted
When burning fossil fuels in an engine how are nitrogen oxides formed?
Nitrogen from the air is oxidised at high temperatures inside the engine
What 2 compounds can form acid rain?
Suflur dioxide and nitrogen oxides
What are 2 negative effects of acid rain?
It makes the soil more acidic, harming plants and damages certain buildings and statues
Other than acid rain, what problem is caused by sulfur dioxide and nitrogen oxides?
Respiratory problems in humans
What properties do shorter chain hydrocarbons have?
They have lower melting and boiling points and are therefore more flammable and more volatile
What is cracking?
Cracking is the process by which larger chain hydrocarbons are split into smaller, more useful hydrocarbons
What type of reaction is cracking?
A thermal decomposition reaction
How does catalytic cracking work?
Some long chain alkanes are heated until they vaporise into a gas, they are then passed over a hot aluminium oxide catalyst. This breaks the long chain alkane into a shorter chain alkane and an alkene
How is steam cracking different to catalytic cracking?
In steam cracking there is no catalyst involved and the vaporised long chain alkane is mixed with steam at very high temperatures
What is an alkene?
Hydrocarbons with a double bond between 2 carbon atoms
Why are alkenes produced when long chain alkanes are cracked?
There aren’t enough hydrogen atoms to make 2 alkanes
What is the difference between alkanes and alkenes?
Alkenes have a double bond between 2 carbon atoms whereas alkanes only have single bonds; alkanes are saturated, alkenes are unsaturated
Does the double bond in alkenes affect their reactivity?
The double bond in alkenes makes them more reactive
What is the bromine test for alkenes?
The substance is mixed with bromine dissolved in water, which is orange. If it comes into contact with an alkene, all the bromine will react, so the solution turns colourless
Why doesn’t the bromine test work for alkanes?
Alkanes are not reactive enough to react with the bromine
What is the composition of the atmosphere?
Nitrogen: 78%
Oxygen: 21%
Argon: Almost 1%
Carbon dioxide: 0.04%
What are the properties of magnesium?
Burns with a bright white flame, forms a white powder of magnesium oxide and is alkaline when dissolved in water
What are the properties of hydrogen?
Burns easily, producing a pale blue flame, and forms water vapour when burnt
What are the properties of sulfur?
burns with a pale blue flame, forms sulfur dioxide and is acidic when dissolved in water
What is thermal decomposition?
Thermal decomposition means to break something down using heat
What happens when you heat a metal carbonate?
It will break up into a metal oxide and carbon dioxide
What is the colour change when copper(II) carbonate decomposes to copper(II) oxide?
Green to black
How old is Earth?
Around 4.6 billion years old
In the first billion years, where did the gases in the Earth’s atmosphere come from?
Volcanic activity
In the first billion years what gasses did volcanoes primarily release into the atmosphere?
Water vapour and carbon dioxide
What happened when the earth cooled?
The water vapour condensed to form oceans in which the carbon dioxide dissolved and formed precipitates of carbonates, drastically reducing the amount of carbon dioxide and water vapour in the atmosphere
Starting 2.7 billion years ago, what process started to reduce the amount of carbon dioxide and increase the amount of oxygen in the awtmosphere?
Photosynthesis by plants and algae
What is the formula for photosynthesis?
Carbon dioxide + water –> Oxygen + glucose
What happened when photosynthetic organisms died?
The carbon they contained became trapped in sedimentary rocks and fossil fuels
What is the atmosphere?
A layer of gases surrounding the earth that is held in place by gravity
What are 3 greenhouse gases?
Carbon dioxide, methane and water vapour
What is the greenhouse effect?
Solar radiation from the sun passes through the atmosphere and hits the earth, some energy is reflected back towards space and some is absorbed by the earth. Some of the most of the reflected energy is absorbed by greenhouse gases that re-emit the energy, repeating the process. The trapped energy keeps the atmosphere warmer and more stable than it would otherwise be
What is the difference between climate change and global warming?
Global warming refers to the overall increase in the Earth’s temperature. Climate change is a consequence of global warming and refers to the effect on the climate, such as large shifts in weather patterns
What is the effect of global warming on the ice caps?
It is causing them to melt, increasing the volume of water in the ocean, which could lead to seasonal flooding. Water also expands when heated which would further increase its volume
What is the difference between climate and temperature?
Climate refers to the typical weather conditions in a region for a very long time and weather refers to the short term atmospheric conditions
