C1Proportion of oxygen in the atmosphere

How to test for proportion of oxygen in the atmosphereTo test the percentage of oxygen in the air you could use 100cm³ of air. The copper will use the oxygen in the reaction. When the reaction is finished there should be about 80cm³ of air left. This means that 20% of the air was oxygen.

The Rock cycleSedimentary Rock-

Formed when layers of sediment built up in lakes and seas. The weight of the water squeezes out any water in between the

sediment E.g. Limestone and chalk

Metamorphic Rock-

Formed by the heat and pressure on sedimentary or igneous rocks If it doesn’t melt, then it is metamorphic. If it does it will become

magma. E.g. Marble

Igneous Rock-

Formed when magma cools down If it cools quickly, it is extrusive. This means it will have small crystals If it cools slowly, it is intrusive. This means it will have large crystals E.g. Granite

Thermal decompositionHow a substance decomposes when heat is applied. For example:

Calcium carbonate   calcium oxide + carbon dioxide

When Carbonates are thermally decomposed, carbon dioxide is formed.

Metal Carbonates form their oxide and Carbon dioxide

E.g. Zinc Carbonate can be heated to form Zinc oxide and Carbon dioxide

Neutralisation Reaction

Acid = PH lower than 7

Base = PH higher than 7

Alkali = A base that is dissolved in water

How can Calcium Hydroxide be producedWhen water is added to calcium oxide, Calcium hydroxide is formed.

E.g.

Calcium is an Alkali and can be used to quickly neutralise acidic soil. It can also be dissolved in water to form lime water.

State Symbols

PH lower than 7 PH Higher than 7

Salt formationSalts are formed through the neutralisation reaction. However, different salts are formed from different acids.

An Acid and a Metal makes a salt

Metal Carbonates

e.g.

Hazard Symbols

Metal Oxides and Metal HydroxidesMetal oxides and Metal hydroxides are often basses which means it can be neutralised with acids to form a salt and water

ElectrolysisDC current applied to an electrolyte. Positively charged ions will be attracted to the cathode (-). Negatively charged ions will be attracted to the anode (+). This is because opposite charges attract.

ChlorineChlorine can be produced by electrolysing sodium chloride solution. Chlorine can be used to treat water supplies. This is because it can kill bacteria and micro-organisms so the water is safe to drink. It is also used in the manufacture of bleach and PVC.

BauxiteBauxite is the main ore for aluminium. The bauxite is melted down to form the electrolyte needed for electrolysis. When the current is applied, the molten aluminium will sink to the bottom.

Test for chlorineChlorine bleaches damp litmus paper white

Test for hydrogenWhen a lighted splint is applied, it will make a squeaky pop sound if hydrogen is present.

Test for oxygenA glowing split will relight in a test tube of oxygen.

Extraction from oreWhere a metal is on the reactivity series effects how it is extracted. If it is below carbon, it can be extractred by a reduction reaction with carbon. This is done by heating the metal with carbon. Metals more reactive than carbon are extracted using eloectrolysis.

Metals such as gold are found unombined. This meand it can be easily removed from its ore.

Oxidisation and reductionIn the oxidation and reduction reaction below. Copper dioxide is reduced. This means oxygen is removed. Carbon is therefore oxidised. This means it is gaining oxygen.

Properties of MetalsTypical properties:

Strong (but can be bent or hammered into shape) Conduct heat Conduct electricity

Aluminium:

Low density Corrosion-resistant Pure aluminium isn’t strong but can be in alloys

Copper:

Hard Strong High melting point Good conductor of electricity Good for water pipes (Below hydrogen in the reactivity series so doesn’t

react with water)

Gold:

Shiny

Easy to shape Non-reactive

Corrosion of MetalsMetals higher up in the reactivity series are more likely to corrode as they react more easily with oxygen

Iron Iron that is extracted in a blast furnace is only 96% iron. These impurities make the iron brittle so it doesn’t have many uses. When these impurities are removed, the iron atoms are all the same size. The layers of iron atoms can then slide over each other. This means the iron is too bendy for most uses.

SteelSteel is produced when small amounts of carbon are added to iron to form an alloy.

Shape memory alloysThese are metal alloys that can go back to its original shape. An example of this is nitinol. This is made from nickel and titanium. When heated, it returns back to its original shape. This can be used in glasses frames or stents for damaged blood vessels.

HydrocarbonsA hydrocarbon is an atom made up of only hydrogen and carbon. It can be found in crude oil. Hydrocarbons can be seperated int sizes using fractional distilation

Fractional Distilation

Fractional Distilation Uses

Complete CombustionOccurs when there is enough oxygen

Incomplete CombustionOccurs when there is not enough oxygen

Choosing FuelsWhen choosing a fuel there are 4 things you need to consider:

Ease of ignition Energy value (amount of energy released) How much ash and smoke it leaves behind Storage and transport

Problems of Burning Fossil FuelsWhen fossil fuels are burnt, carbon dioxide and water vapour are released into the air. Sulfur impurities are also released into the atmosphere. If there is not enough oxygen, It will not burn properly and will release carbon soot and carbon monoxide into the atmosphere.

Acid Rain Acid rain is formed when sulfuric acid from power stations and cars etc. mix with clouds to form dilute sulfuric acid. This falls as acid rain. Acid rain can acidify lakes and ponds killing plants and animals that live in it. It can also damage trees, limestone buildings and stone statues.

Sulfur can be removed from fuels before they are burnt. This however, costs more money and uses more fossil fuels to do so.

Acid gas scrubbers use calcium carbonate to clean up fumes from power stations before it enters the environment.

Cars are now fitted with catalytic converters turn harmful gases into cleaner gases.

Greenhouse GasesGreenhouse gases such as carbon dioxide, methane and water vapour, act as an insulating layer that blocks in radiation from the sun. This is causing our planet to heat up (global warming).

Reducing Carbon Dioxide LevelsIron seedingIron is needed for photosynthesis. If it is injected into the upper levels of the sea, then the growth of phytoplankton is promoted. These phytoplankton

remove Carbon dioxide from the air through photosynthesis and put out oxygen.

However, some phytoplankton grow to become toxic. Micro-organisms that feed on dead plankton use up oxygen. This creates ‘dead zones’ in the sea where nothing can live.

Converting Carbon Dioxide to HydrocarbonsScientists have been trying to find a way to convert carbon dioxide back into hydrocarbons. They have managed to convert carbon dioxide into small chains of hydrocarbons but making long chains needed for petrol is more challenging.

BiofuelsBiogasBiogas is produced when micro-organisms decompose animal waste or dead plants. This is because they build up carbon dioxide when they are alive, and when they die, this is released. This biogas can be burnt to produce heat to turn a turbine or can be used for heating

Advantages DisadvantageRenewable Less land to grow foodEasy to replace as crops grow quickly Large storage space Carbon neutral (No carbon is released into the atmosphere)

Highly flammable (hard to store)

Clean fuel (there are few pollutants released)Cheap

BioethanolSugar beet and sugar cane can be fermented with yeast to form ethanol (alcohol). If you add 90% petrol to it, you create Gasohol. Cars can run from this.

Advantages DisadvantageLess crude oil is required Less land to grow foodCarbon neutral (Doesn’t release carbon dioxide)

Requires suitable climate to grow the sugar beet and sugar cane

Clean fuel (Few pollutants) Distillation is needed after fermentation. This uses electricityPollutants include carbon dioxide and water vapour. These are greenhouse gases.

Hydrogen fuel cellLike a battery, it can produce energy. It takes in hydrogen and oxygen and creates water and energy.

Advantage DisadvantageNo pollutants Gases require large storage spaceNo recharging required Flammable (Hard to store)More than 80% efficient Hydrogen still needs to be obtained

through electrolysis.Less energy lost through heat and friction

Measuring energy content in fuels1. Measure fuel mass before2. Measure out volume of water into a beaker3. Add a draft shield to prevent the flame from being blown away from the

water4. Measure temperature of the water5. Light the fuel until the water rises 10 degrees6. Then blow out the flame and re-measure the fuel.7. Calculate the difference8. Repeat with another fuel

The fuel that has used the least fuel is the best fuel.

CrackingHeat and a catalyst are applied to long chains of hydrocarbons. This causes them to break into smaller chains. This process is useful as long chains of hydrocarbons have limited uses.

1. Heat is applied to the alkane and the catalyst

2. As the alkane passes over the catalyst, it will crack into smaller hydrocarbons.

3. These smaller hydrocarbons go down the delivery tube and into the jar.

When you heat the boiling tube, it expands. If you kill the heat, the glass will shrink back to its original size. This creates a vacuum which sucks in the cold water. When the cold water comes into contact with the hot glass, the glass will shatter.

Polymerisation Polymers are made up of repeated links called monomers. Pressure and a catalyst are applied to alkenes. This breaks open the double bond, allowing it to join other monomers. When ethene is turned into a polymer, poly (ethene) is produced.

Chemical Formula

Monomers Polymers

Uses of synthetic polymers

Problems with plastics

Solutions

Alkanes and Alkenes

Alkanes are saturated and doesn’t change the colour of bromine water.

Alkenes are unsaturated and decolourises bromine water.

Drawing alkanes

1. Draw the carbons

2. Draw the bonds. Alkanes have one double bond.

3. Carbons can only have 4 bonds. Count how many they have already used up and add more so it has a total of 4 bonds

4. Then add the Hydrogens

CrackingThermal decomposition reaction. This can break down long chains of hydrocarbons into smaller more useful hydrocarbons. This can be done by the use of heat and a catalyst.

1. Heat the alkane and catalyst at the same time.

2. As the alkane starts to condense, it will pass over the catalyst. This causes it to crack into alkenes.

3. The alkenes will then pass the through the delivery tube and up into the beaker.

4. The water will be pushed out of the beaker and you will be left with alkenes.

5. You can then test it with bromine water. It should decolourise. This proves that it is an alkene not an alkane.

Polymerisation Polymers are long chains of repeated monomers. These can be created by the use of pressure and a catalyst. An example of this is the monomer glucose forming the polymer starch.

The polymer, polyethene can be created when the double bond in the monomer, ethene breaks open and allows many other monomers to join.

Polymer properties and uses to remember-