Revision for C1 C1 1 Fundamental ideas C1 2 Rocks and building materials C1 3 Metals and their uses C1 4 Crude oil and fuels C1 5 Products from oil C1 6 Plant oils C1 7 Our changing planet

C1 1.1, 1.2 and 1.3 Atoms are made up of protons, neutrons and electrons. Particle Charge Mass Proton +1 1 Neutron Electron -1 Nucleus Electrons are arranged in energy levels (shells). The fourth shell can hold 18 electrons (but you don’t need to go that far). The first shell can hold 2 electrons. All atoms want a full outer shell of electrons, and they will do that by gaining electrons, losing electrons or sharing electrons. The second shell can hold 8 electrons. The third shell can hold 8 electrons. Electron configurations can be written 2,8,8,18.

Electrons gained/lost C1 1.4 Forming bonds A metal atom gives electrons to a non-metal atom, so that both of them have full outer shells. When drawing the electron configuration for an ion, we draw square brackets around it, and put the charge on the outside. Electron configurations can be written Na [2,8]+ and Cl [2,8,8]- Na + Cl - We draw the electrons as different shapes to show which atom they came from (dot and cross diagrams) Charges on ions from different groups Group 1 2 3 4 5 6 7 8 Outer shell electrons Electrons gained/lost Loses 1 Loses Loses 3 N/A Gains 3 Gains 2 Gains 1 Ion charge + 2+ 3+ 3- 2- -

C1 1.4 Forming bonds + 2 Mg2+ F- MgF2 - - Mg F F If the positive and negative ions have different charges, then you will need different numbers of ions to balance out the charge e.g. MgF2. F - Mg + 2 F - Remember: Swap n’ drop Compound ions Swap the ion charge numbers, and drop them down to the bottom right of the element symbol. Get rid of the charge. These ions are on your data sheet, so you don’t need to remember them. If your compound has a compound ion (OH-, NO3-, SO42-, CO32-, NH4+) and there is more than one of them, you need to put it in brackets. E.G Mg(NO3)2, or (NH4)2O, or Al2(SO4)3 Mg2+ F- MgF2

simplified dot and cross diagram C1 1.4 Forming bonds Covalent bonding is a shared pair of electrons. covalent bond Covalent bonding occurs between non metals. Group 4 elements share 4 electrons. Group 5 elements share 3 electrons. Group 6 elements share 2 electrons. Group 7 elements and hydrogen share 1 electron. F F F simplified dot and cross diagram H N H O solid line (one line = 1 pair) F – H Cl O C

+ + Balancing equations CH4 + 2O2  CO2 + 2H2O There are 4 hydrogens here. You multiply the big number by the little number. There are 4 hydrogens here, bonded together. There are 2 molecules of oxygen not bonded together. You can only change the BIG numbers in equations – we cannot change the small numbers or add or take away any reactants or products.

C1 2.1 Limestone and its uses Carbon dioxide is formed from thermal decomposition of limestone and from burning methane. Argon and nitrogen come from the air. Calcium carbonate Calcium oxide Carbon dioxide Reaction of thermal decomposition limestone. CaCO3  CaO + CO2 Methane is fuel for the fire to heat limestone.

C1 2.2 Reactions of carbonates Limestone is heated and breaks down (thermal decomposition) into calcium oxide (quicklime) and carbon dioxide. CaCO3(s)  CaO(s) + CO2(g) CaO(s) + H2O(l)  Ca(OH)2(s) Ca(OH)2(s)  Ca(OH)2(aq) Ca(OH)2(aq) + CO2(g)  CaCO3(s) + H2O(l) Calcium oxide (quicklime) is added to water to make solid calcium hydroxide (slaked lime). Solid calcium hydroxide (slaked lime) is dissolved in water to make aqueous calcium hydroxide (lime water). Aqueous calcium hydroxide (lime water) is added to carbon dioxide which makes calcium carbonate and water.

C1 2.3 Limestone reaction cycle and C1 2.4 cement and concrete + Sand + Water + Gravel Concrete Cement + Sand + Water Mortar + Clay Limestone CaO HEAT + Calcium Carbonate Calcium Oxide Carbon Dioxide CaCO3 + Water CO2 Calcium Hydroxide Limewater Ca(OH)2

C1 2.5 Limestone issues Limestone quarrying has many advantages and disadvantages: Advantages It creates jobs It provides building materials nearby Disadvantages Pollution Noise pollution It ruins the landscape

C1 3.1 Extraction of metals Extracted using electrolysis. Extracted using reduction by carbon. Reduction is a reaction that removes oxygen from the metal oxide. Found as elements (native).

C1 3.2 Extraction of iron Carbon + oxygen  Carbon dioxide C + O2  CO2 Carbon dioxide + carbon  Carbon monoxide CO2 + C  2CO Iron oxide + carbon monoxide  Iron + carbon dioxide Fe2O3 + 3CO  2Fe + 3CO2 Iron oxide + carbon  Iron + carbon dioxide 2Fe2O3 + 3C  4Fe + 3CO2 The iron produced in the blast furnace is 4% carbon. This is called pig iron. Pure iron is arranged in layers . When an atom is struck, the whole layer moves. Pure iron is malleable. Pig iron is very brittle because the atoms are not in layers due to the carbon atoms disrupting the layers.

Steel Composition Uses Low carbon steel Iron, carbon (0.1%) Cars, buildings and bridges High carbon steel Iron, carbon (1.5%) Tools, knives and swords Low alloy steels Iron, carbon, manganese, nickel Cars, trucks, bridges High alloy steels Iron, carbon, chromium Tools, armour Stainless steels Iron, carbon, nickel, chromium Cutlery, saucepans, medical instruments. Tungsten steel Iron, carbon, tungsten Drill bits C1 3.2 Steels Steels are mixtures of iron, carbon and possibly other metals. Steels are alloys. Alloys are stronger than pure metals because they disrupt the layers of the metals and stop them sliding over each other. Pure iron is arranged in layers . When an atom is struck, the whole layer moves. Pure iron is malleable. The layers of alloys are disrupted, so they stop the layers of metal atoms sliding over each other.

Aluminium and titanium C1 3.3 Aluminium and titanium Aluminium is too reactive to extract from its ore using carbon, so it is extracted using electrolysis. Aluminium is light and strong. It is used for aircraft, foil, drinks cans, saucepans and bicycles. Titanium is not reactive, but if carbon is used to displace it, it will form brittle titanium carbide. Instead, titanium oxide is reacted with chlorine to make titanium chloride. It is then reacted with sodium to make titanium. This is expensive as the sodium needs to be extracted using electrolysis.

Copper sulphide + oxygen  Copper + sulphur dioxide C1 3.4 Extraction of copper and C1 3.6 metallic issues. Copper sulphide + oxygen  Copper + sulphur dioxide This is called smelting. Sulphur dioxide causes acid rain. The copper then undergoes electrolysis in order to purify it. Copper can also be extracted by phytomining. Plants take up copper from the soil. The plants are then burnt and the ashes are put in sulphuric acid. Scrap iron is added to the copper sulphate to displace it. Iron + copper sulphate  Copper + iron sulphate Copper can also be extracted by bioleaching. Bacteria feed on copper ores to get copper solutions. These solutions are also reacted with iron to extract the copper. Iron + copper sulphate  Copper + iron sulphate

C1 chapter 3.5 Useful metals and C1 3.6 metallic issues. They have the following properties: Shiny Malleable Hard Strong High melting point Sonorous Conducts electricity Conducts heat It is good to recycle metals because it saves energy from extracting them. It reduces pollution as the vehicles are no longer needed to excavate them and it means that less ore is used up.

C1 chapter 4.1 Crude oil Crude oil is a mixture of lots of different chemicals called alkanes. Alkanes only contain hydrogen and carbon (hydrocarbons) an they have all single bonds (they are saturated) and have a general formula of CnH2n+2.

C1 4.1 Alkanes Shorter chain alkanes have: Longer chain alkanes have: Lower boiling points. Low viscosity. High flammability. Longer chain alkanes have: Higher boiling points. High viscosity. Less flammability.

Fractional distillation In fractional distillation, crude oil is heated up. Smaller alkanes have lower boiling points and they go to the top. Larger alkanes have larger boiling points and they stay at the bottom. The crude oil is split into fractions. Each fraction has a use.

C1 4.3 and C1 4.4 Burning fuels and Cleaner fuels.

C1 4.5 Alternative fuels Hydrogen Made from electrolysis of water. Advantages It burns cleanly. Obtained from water Disadvantages Requires electricity. Explosive. Needs larger volume to store. Biodiesel Biodiesel is fuel from plant or animal products, such as vegetable oils or animal waste. Advantages It burns cleanly. It is carbon neutral. It is less harmful to plants and animals. Disadvantages It needs land that should be used for food. It destroys habitats. Ethanol Made by fermenting sugar from plants. Advantages It burns cleanly. It is carbon neutral. Disadvantages It needs land that should be used for food. It destroys habitats.

C1 5.1 Cracking hydrocarbons Alkenes – Alkenes are hydrocarbons (made up of carbon and hydrogen) with a carbon-carbon double bond (C=C). They have the general formula CnH2n (2 hydrogens for every carbon). You can use bromine water to work out if you have an alkene. Bromine water is brown. Alkenes make it colourless. Alkanes do not change the colour (it stays brown). Cracking – this is when a large alkane is turned into a smaller alkane and an alkene.

C1 5.2 Making polymers from alkenes An individual alkene is called a monomer (mono = one, mer = part). When they are joined together, they become a polymer (poly = many) If alkenes are put under a high temperature and pressure, then they all link up to form a long chain called a polymer. An individual unit is in square brackets. The lines show that it is bonded to monomers outside the brackets. n = a big number

C1 5.3 New and useful polymers Hydrogels are polymers that can trap water inside them. They can be used as contact lenses or dressings for burns. Stitches can be made from shape memory polymers which tighten to just the right tightness to close a wound. Eventually, when the wound is healed, they dissolve away. Plasters can be made from light sensitive polymers that lose their stickiness when exposed to light. Instead of ripping the plaster off, you can just rip the cover off which makes the plaster fall away.

C1 5.4 Plastic waste Advantages Easy Relatively cheap Quick   Landfill Incineration Recycling Biodegradable plastics Advantages Easy Relatively cheap Quick The plastics can be used as fuel. Saves energy and resources. Saves landfill space. Preserves crude oil supplies. Tropical forests are destroyed to create farm land. Disadvantages Uses up land The plastics stay for centuries Causes pollution Takes time and fuel (to transport and sort). Recycled plastic is never as strong as original plastic. Needs land space to grow crops (reduces land space to grow food)

C1 5.5 Ethanol Ethanol can be used as a fuel or a solvent. Ethanol can be made by fermentation Sugar (glucose) Ethanol + carbon dioxide C6H12O6 2C2H5OH + 2 CO2 yeast Sugar is a renewable resource, but it needs land to grow, which would take away land needed to grow food. Ethanol can also be made by hydration (Adding water to) ethene. Ethene + steam Ethanol C2H4 + H2O C2H5OH Phosphoric acid catalyst Ethene is from crude oil, so this method is non renewable. It does produce pure ethanol, however. Ethanol can be used as a fuel or a solvent.

C1 6.1 Extracting vegatable oil Plants use energy from the sun to make glucose. They then turn this glucose into other chemicals, such as vegetable oil. Carbon dioxide + water Glucose + oxygen Chlorophyll Sunlight 6CO2 + 6H2O C6H12O6 + 6O2 Vegatable oils are unsaturated (they have carbon-carbon double bonds). Animal fats are saturated (they have no double bonds). Vegatable oils are liquids at room temperature. Animal fats are solids at room temperature. Animal fat Vegetable oil

vs C H C H H H + C1 6.2 Cooking with vegetable oils Cooking things in oil (compared to cooking things in water) cooks them more quickly (because oil has a higher boiling point), makes the outside of the food change colour and crispier, and makes the inside softer. Foods cooked in oil have more energy than foods cooked in water. vs Cooking in water. Cooking in oil. Hydrogenation of vegetable oils Unsaturated vegetable oil Hardened vegetable oil C H C H Nickel 60oC H H +

C1 6.3 Everyday emulsions Water Oil When water and oil mix, little droplets of oil form in the water. This mixture is called an emulsion. However, water and oil do not mix easily (they are immiscible), so they end up like this. We use emulsifiers to help oil and water mix. Emulsifiers have two parts –a head that mixes with water (hydrophilic) and a tail that mixes with oil (hydrophobic). This is how emulsifiers help oil and water mix. Water Oil Emulsifiers can be used to help make mayonnaise and detergents to help wash up oily pans.

C1 6.4 Food issues A food additive is a substance that is added to a food to improve its taste, preserve it or change its colour. All food additives in our food have an E number to prove that they have passed a safety standard. Emulsifiers have an E number that begins with 4. Emulsifers stop oil and water based substances from separating. Emulsifiers are needed in chocolate, mayonaise and ice cream. So emulsifers make foods with lots of energy easier to eat and so it is tempting to eat more fatty food. Vegetable oils are healthier than animal fats. They contain vitamin E and they are better for the heart than animal fats. vs

C1 7.1 Structure of the Earth Atmosphere Crust Mantle Core About 100km from the surface to the top. 5 – 70km thick 3000km thick 3500km in diameter Made of 78% nitrogen, 21% oxygen, 1% argon and 0.04% carbon dioxide. We collect the gases from the atmosphere to use. Made of rock. We get minerals from the crust and the oceans. Semi liquid. It can flow very slowly. The crust floats on top of it. Made of iron and nickel. The outer part is liquid due to the high temperature and the inner part is solid due to the high pressure. We know what the inside of the earth is like from earthquake data. The way the earthquake waves bend tell us the density of the substances below the surface.

C1 7.2 The restless Earth The Earth’s crust is split into sections called plates. The plate boundaries are where we find earthquakes, volcanoes and mountains. Mountains form when two plates move together. Earthquakes occur when two plates rub side by side. Plates move because they are floating on top of the semi-liquid mantle. Radioactive processes in the mantle release heat which make convection currents which make the plates move. Alfred Wegener came up with the theory of plate tectonics. His evidence was that fossils and rocks on different continents were similar, indicating that they were once joined. However, this was also supported by the idea of a land bridge which connected South America and Africa. His theories were not accepted until 50 years later when scientists discovered something called seafloor spreading.

C1 7.3 The Earth’s atmosphere in the past 4 Billion years ago Earth’s atmosphere was mainly carbon dioxide, with methane, water vapour, nitrogen and ammonia. 4 billion years ago   The oceans are formed when water vapour condensed. 3.4 Billion years ago   Life was formed. It was bacteria that used undersea volcanoes as a source of food. 2.5 Billion years ago   Algae evolved which could use photosynthesis to make food from gases in the atmosphere. 200 million years ago   The Earth’s atmosphere is the same as what it is today. 600 million years ago Animals evolved which could use the oxygen for respiration. 2.5 Billion years ago   The oxygen in the atmosphere reacts with the methane and the ammonia in the atmosphere.

C1 7.4 Life on Earth The Miller-Urey experiment took place in 1953. The scientists took the substances that were in the atmosphere billions years ago. They used water, methane, ammonia and hydrogen and passed an electric spark through them. They got 11 amino acids.

C1 7.5 Gases in the atmosphere Carbon dioxide has been ‘locked into’ rocks such as limestone. Ammonia and methane in the atmosphere reacted with oxygen to form carbon dioxide, water and nitrogen. The gases in the atmosphere can be removed by fractional distillation. The gases are cooled to a temperature below -200oC and gradually heated up. Nitrogen boils off first at -196oC. CH4 + 2O2  CO2 + 2H2O 4NH3 + 3O2  2N2 + 6H2O

C1 7.6 Carbon dioxide in the atmosphere The carbon cycle Respiration hotosynthesis espiration issolves alcium arbonate imestone Sedimentation lants nimals Since the 1960s, the amount of carbon dioxide in the atmosphere has increased. This may be due to burning fossil fuels. Some of the carbon dioxide is absorbed into the oceans. This makes them more acidic, which reacts with coral reefs.