Products from calcium carbonateFor your exam, you need to know how calcium hydroxide is obtained from calcium carbonate.Making calcium oxideIf calcium carbonate is heated strongly, it breaks down to form calcium oxide and carbon dioxide. Calcium oxide is yellow when hot, but white when cold. Here are the equations for this reaction:calcium carbonate calcium oxide + carbon dioxideCaCO3 CaO + CO2This is a thermal decomposition reaction.Making calcium hydroxideCalcium oxide reacts with water to form calcium hydroxide, which is an alkali. Here are the equations for this reaction:calcium oxide + water calcium hydroxideCaO + H2O Ca(OH)2A lot of heat is produced in the reaction, which may even cause the water to boil.Uses of limestoneLimestone is a type of rock, mainly composed of calcium carbonate. Limestone is quarried (dug out of the ground) and used as a building material. It is also used in the manufacture of cement, mortar and concrete.Reactions with acidsCarbonates react with acids to produce carbon dioxide, a salt and water. For example:calcium carbonate + hydrochloric acid carbon dioxide + calcium chloride + waterCaCO3 + 2HCl CO2 + CaCl2 + H2OSince limestone is mostly calcium carbonate, it is damaged by acid rain. Sodium carbonate, magnesium carbonate, zinc carbonate and copper carbonate also react with acids: they fizz when in contact with acids, and the carbon dioxide released can be detected using limewater.The main advantages and disadvantages of the limestone industryAdvantagesDisadvantages

Limestone is a valuable natural resource, used to make things such as glass and concrete. Limestone quarries are visible from long distances and may permanently disfigure the local environment.

Limestone quarrying provides employment opportunities that support the local economy in towns around the quarry.Quarrying is a heavy industry that creates noise and heavy traffic, which damages people's quality of life.

Reactivity and extraction methodMetals (in decreasing order of reactivity)Method of extraction

potassium sodium calcium magnesium aluminiumextract by electrolysis

carbon

zinc iron tin leadextract by reaction with carbon or carbon monoxide

hydrogen

copper silver gold platinumextracted in various ways

The method of extraction of a metal from its ore depends on the metal's position in the reactivity series.Gold, because it is so unreactive, is found as the native metal and not as a compound. It does not need to be chemically extracted from its ore, but chemical reactions may be needed to remove other elements that might contaminate the metal.Pure copper, gold, iron and aluminium are too soft for many uses. They are mixed with other similar metals to make them harder for everyday use. For example: brass, used in electrical fittings, is 70 percent copper and 30 percent zinc 18 carat gold, used in jewellery, is 75 percent gold and 25 percent copper and other metals duralumin, used in aircraft manufacture, is 96 percent aluminium and 4 percent copper and other metals. Steel Carbon is removed from molten iron by blowing oxygen into it. The oxygen reacts with the carbon, producing carbon monoxide and carbon dioxide, which escape from the molten metal. Enough oxygen is used to achieve steel with the desired carbon content. Other metals are often added, such as vanadium and chromium, to produce alloys with properties suited to specific uses.Distillation process to separate ethanol from water

Step 3 - the water left evaporates, cools, then condenses1. Back2. 13. 24. 35. NextThe mixture is heated in a flask. Ethanol has a lower boiling point than water so it evaporates first. The ethanol vapour is then cooled and condensed inside the condenser to form a pure liquid.The thermometer shows the boiling point of the pure ethanol liquid. When all the ethanol has evaporated from the solution, the temperature rises and the water evaporates.This is the sequence of events in distillation:heating evaporating cooling condensingAs you go up the fractionating column, the hydrocarbons have: lower boiling points lower viscosity (they flow more easily) higher flammability (they ignite more easily).This means that in general hydrocarbons with small molecules make better fuels than hydrocarbons with large molecules.Testing for unsaturationBromine water is a dilute solution of bromine, normally orange-brown in colour. It becomes colourless when shaken with an alkene, but its colour remains the same when it is shaken with alkanes.Your web browser does not have JavaScript switched on at the moment. For information on how to enable JavaScript please go to the Webwise site.< p>You will not be able to see this content until you have JavaScript switched on. The bromine water test is a test for unsaturation.Examples of polymers and their usesPolymerTypical use

polytheneplastic bags and bottles

polypropenecrates and ropes

polychloroethenewater pipes and insulation on electricity cables

Polymers have properties that depend on the chemicals they are made from, and the conditions in which they are made. For example, there are two main types of poly(ethene): LDPE, low-density poly(ethene), is weaker than HDPE, high-density poly(ethene), and becomes softer at lower temperatures. Modern polymers have many uses, including: new packaging materials waterproof coatings for fabrics (such as for outdoor clothing) fillings for teeth dressings for cuts hydrogels (for example for soft contact lenses and disposable nappy liners) smart materials (for example shape memory polymers for shrink-wrap Making ethanol from ethene and steam Ethanol can be made by reacting ethene (from cracking crude oil fractions) with steam. A catalyst of phosphoric acid is used to ensure a fast reaction. ethene + steam ethanol C2H4 + H2O C2H5OH Notice that ethanol is the only product. The process is continuous as long as ethene and steam are fed into one end of the reaction vessel, ethanol will be produced. These features make it an efficient process, but there is a problem. Ethene is made from crude oil, which is a non-renewable resource. It cannot be replaced once it is used up and it will run out one day. Fermentation Sugar from plant material is converted into ethanol and carbon dioxide by fermentation. The enzymes found in single-celled fungi (yeast) are the natural catalysts that can make this process happen. C66H12O6 2C2H5OH + 2CO2 Unlike ethene, sugar from plant material is a renewable resource.Emulsifiers- Higher tierEmulsifier molecules have two different ends: a hydrophilic end - 'water-loving' - that forms chemical bonds with water but not with oils a hydrophobic end - 'water-hating' - that forms chemical bonds with oils but not with water.Lecithin is an emulsifier commonly used in foods. It is obtained from oil seeds and is a mixture of different substances. A molecular model of one of these substances is seen in the diagram.

Emulsifier moleculesThe hydrophilic 'head' dissolves in the water and the hydrophobic 'tail' dissolves in the oil. In this way, the water and oil droplets become unable to separate out.Double bonds and hydrogenationBromine water testUnsaturated vegetable oils contain double carbon-carbon bonds. These can be detected using bromine water (just as alkenes can be detected). Bromine water becomes colourless when shaken with an unsaturated vegetable oil, but it stays orange-brown when shaken with a saturated vegetable fat. Bromine water can also be used to determine the amount of unsaturation of a vegetable oil. The more unsaturated a vegetable oil is, the more bromine water it can decolourise. Hydrogenation- Higher tierSaturated vegetable fats are solid at room temperature, and have a higher melting point than unsaturated oils. This makes them suitable for making margarine, or for commercial use in the making of cakes and pastry. Unsaturated vegetable oils can be hardened by reacting them with hydrogen, a reaction called hydrogenation.During hydrogenation, vegetable oils are reacted with hydrogen gas at about 60C. A nickel catalyst is used to speed up the reaction. The double bonds are converted to single bonds in the reaction. In this way unsaturated fats can be made into saturated fats they are hardened.

The structure of part of a fatty acidNow try a Test Bite.Page: 1. 12. 23. 34. 41. Back2. NextBack to Plant oils and their uses indexActivityExamples of sedimentary rockSedimentary rocks contain rounded grains in layers. Examples of sedimentary rock are:

Sedimentary rocks like sandstone have layers chalk limestone sandstone shale.The oldest layers are at the bottom and the youngest layers are at the top. Sedimentary rocks may contain fossils of animals and plants trapped in the sediments as the rock was formed. Sedimentary rocks are often quite soft and are susceptible to erosion.Examples of sedimentary rockSedimentary rocks contain rounded grains in layers. Examples of sedimentary rock are:

Sedimentary rocks like sandstone have layers chalk limestone sandstone shale.The oldest layers are at the bottom and the youngest layers are at the top. Sedimentary rocks may contain fossils of animals and plants trapped in the sediments as the rock was formed. Sedimentary rocks are often quite soft and are susceptible to erosion.Examples of sedimentary rockSedimentary rocks contain rounded grains in layers. Examples of sedimentary rock are:

Sedimentary rocks like sandstone have layers chalk limestone sandstone shale.The oldest layers are at the bottom and the youngest layers are at the top. Sedimentary rocks may contain fossils of animals and plants trapped in the sediments as the rock was formed. Sedimentary rocks are often quite soft and are susceptible to erosion.Examples of sedimentary rockSedimentary rocks contain rounded grains in layers. Examples of sedimentary rock are:

Sedimentary rocks like sandstone have layers chalk limestone sandstone shale.The oldest layers are at the bottom and the youngest layers are at the top. Sedimentary rocks may contain fossils of animals and plants trapped in the sediments as the rock was formed. Sedimentary rocks are often quite soft and are susceptible to erosion.Formation of metamorphic rock

Slate quarry, CullipoolMetamorphic rock has been subjected to tremendous heat and / or pressure, which caused it to change into another type of rock. It is usually resistant to weathering and erosion and is therefore very hard wearing.Examples of metamorphic rockExamples include marble - which originates from chalk or limestone, slate - which originates from clay, and schists formed from sandstone or shale (sedimentary rocks).Advantages and disadvantages of various building materialsLimestone, cement and mortar slowly react with carbon dioxide dissolved in rainwater, and wear away. This damages walls made from limestone, and it leaves gaps between bricks in buildings. These gaps must be filled in or "pointed". Pollution from burning fossil fuels makes the rain more acidic than it should be, and this rain makes these problems worse.Concrete is easily formed into different shapes before it sets hard. It is strong when squashed, but weak when bent or stretched. However, concrete can be made much stronger by reinforcing it with steel. Some people think that concrete buildings and bridges are unattractive.Glass is usually brittle and easily shattered, but toughened glass can be used for windows. While glass is transparent and so lets light into a building, the use of too much glass can make buildings very hot in the summer.Uses of calcium oxideLimestone can be broken down using heat to produce calcium oxide, which has lots of uses. Add water and a vigorous exothermic reaction takes place. This forms calcium hydroxide. Calcium hydroxide is soluble in water and forms a solution known as limewater which is used to test for carbon dioxide. Calcium oxide, calcium hydroxide and calcium carbonate can be used to neutralise soil acidity. Calcium carbonate can be used to remove acidic gases from coal-fired power station chimneys reducing harmful emissions and acid rain. The main advantages and disadvantages of the limestone industryAdvantagesDisadvantages

Limestone is a valuable natural resource, used to make things such as glass and concrete. Limestone quarries are visible from long distances and may permanently disfigure the local environment.

Limestone quarrying provides employment opportunities that support the local economy in towns around the quarry.Quarrying is a heavy industry that creates noise and heavy traffic, which damages people's quality of life.

Some common transition metals and the colours of their precipitates.transition metalcolour of precipitate

iron(II)green - turns orange-brown when left standing

iron(III)orange-brown

copperpale blue

zincwhite

Example of a precipitation reactionHow could you tell if an unknown substance contained iron(II) nitrate or iron(III) nitrate? You would add a few drops of sodium hydroxide solution. If you got a dark green precipitate it would show that the unknown substance was iron(II) nitrate; if you got an orange-brown precipitate it would show that the unknown substance was iron(III) nitrate.Note that it is the metal that determines the colour, so you would get the same result whether you used zinc chloride or zinc nitrate - a white precipitate in this example.What are acids?

Corrosive

IrritantAll acids: have a low pH (1-6) the lower the number the stronger the acid react with bases to form neutral compounds are corrosive when they are strong are an irritant when they are weak.Metal hydroxidesMetal hydroxides, such as sodium hydroxide, usually dissolve in water to form clear, colourless solutions. When an acid reacts with a metal hydroxide, the only products formed are a salt plus water. Here is the general word equation for the reaction:acid + metal hydroxide a salt + waterYou usually observe these things during the reaction: there is a temperature rise the pH of the reaction mixture changes Metal carbonates Although sodium carbonate can dissolve in water, most metal carbonates are not soluble. Calcium carbonate (chalk, limestone and marble) is like this. When an acid reacts with a metal carbonate, the products formed are a salt plus water, but carbon dioxide is also formed. Here is the general word equation for the reaction: acid + metal carbonate a salt + water + carbon dioxide You usually observe bubbles of gas being given off during the reaction. You can show that the gas is carbon dioxide by bubbling it through limewater: this turns cloudy white when it reacts with carbon dioxide. How salts are namedmetal involvedacidsalt

sodium hydroxide reacts withhydrochloric acidto make sodium chloride

potassium hydroxide reacts withsulfuric acid to makepotassium sulfate

copper oxide reacts withhydrochloric acid to makecopper chloride

zinc oxide reacts withsulfuric acid to makezinc sulfate

calcium carbonate reacts withhydrochloric acid to makecalcium chloride

sodium carbonate reacts withsulfuric acid to makesodium sulfate

Here are the word equations and balanced formulae equations for the reactions The process of electrolysisHere is what happens during electrolysis: Positively charged ions move to the negative electrode during electrolysis. They receive electrons and are reduced. Negatively charged ions move to the positive electrode during electrolysis. They lose electrons and are oxidised.Many substances are commonly electrolysed, but here are two examples:Hydrochloric acid Produces chlorine at the positive electrode Produces hydrogen at the negative electrode If the gas produces a squeaky pop from a lighted splint, it is hydrogen If the gas turns blue litmus paper red then white (bleached) it is chlorine.Water Produces oxygen at the positive electrode Produces hydrogen at the negative electrode If the gas relights a glowing splint, it is oxygen. Important uses of products in the chemical industryProductTestUsesProblems

chlorinedamp blue litmus paper turns red (as chlorine is acidic) then white (chlorine is a bleach)manufacture of bleach and PVC (polyvinylchloride) Water treatment toxic gas

hydrogenlighted splint gives a squeaky popmany uses including as a fuelflammable

sodium hydroxideturns red litmus bluecleaning productscorrosive

Aluminium does not rust (corrode) because its surface is protected by a natural layer of aluminium oxide which prevents the metal below from coming into contact with air and oxygen. Unlike rust, which can flake off the surface of iron and steel objects, the layer of aluminium oxide does not flake off.More reactive elements are more likely to oxidise.Factors influencing the choice of a fuel The fossil fuels include coal, oil and natural gas. Various factors need to be considered when deciding how to use a fossil fuel. These include: the energy value of the fuel in J/g of fuel the availability of the fuel how the fuel can be stored the cost of the fuel the toxicity of the fuel - whether it is poisonous any pollution caused when the fuel is used, such as acid rain how easy it is to use the fuel

Factories can cause air pollutionIn general, solids such as coal are easier to store than liquids and gases.Effects of acid rainAcid rain reacts with metals and rocks such as limestone. Buildings and statues are damaged as a result. Acid rain damages the waxy layer on the leaves of trees and makes it more difficult for trees to absorb the minerals they need for healthy growth. They may die as a result. Acid rain also makes rivers and lakes too acidic for some aquatic life to survive.Reducing acid rainSulfur dioxide can be removed from waste gases after combustion of the fuel. This happens in power stations. The sulfur dioxide is treated with powdered limestone to form calcium sulfate. This can be used to make plasterboard for lining interior walls, so turning a harmful product into a useful one.

The process of removing sulfur dioxideSulfur can be removed from fuels at the oil refinery. This makes the fuel more expensive to produce, but it prevents sulfur dioxide being produced. You may have noticed 'low sulfur' petrol and diesel on sale at filling stations.Greenhouse effect

1. The Suns rays enter the Earths atmosphere 2. Heat is reflected back from the Earths surface 3. Heat is absorbed by greenhouse gases, such as carbon dioxide, and as a result becomes trapped in the Earths atmosphere. 4. The Earth becomes hotter as a result Biofuels Biofuels come from the products of living organisms, such as methane biogas from decaying manure and sewage. Vegetable oils are also used as fuels for vehicles. Some of this biodiesel is made from waste cooking oil and rapeseed oil. Advantages of using biofuelsBiofuels are carbon neutral, which means that they release only as much carbon dioxide when they burn as was used to make the original oil by photosynthesis.This helps to reduce global warming.However, some people are concerned about whether it is ethical to use food crops in this way, instead of using them to feed hungry people

Making hydrogenAt the moment, most hydrogen is made by reacting steam with coal or natural gas, which are non-renewable resources.Hydrogen can also be made by passing electricity through water. Unfortunately, most electricity is generated using coal and other fossil fuels: any pollution from burning these fuels just happens at the power station instead of at the vehicle itself. CRACKINGCracking allows large hydrocarbon molecules to be broken down into smaller, more useful hydrocarbon molecules. Fractions containing large hydrocarbon molecules are vaporised and passed over a hot catalyst. This breaks chemical bonds in the molecules, and forms smaller hydrocarbon molecules. Cracking is an example of a thermal decomposition reaction.Some of the smaller molecules formed by cracking are used as fuels, and some of them are used to make polymers in plastics manufacture.Alkenes can act as monomers because they have a double bond: Ethene can polymerise to form poly(ethene), which is also called polythene. Propene can polymerise to form poly(propene), which is also called polypropylene.Different polymers have different properties, so they have different uses. The table below gives some examples.Examples of polymers and their usespolymeruse

polyetheneplastic bags and bottles

polypropenecrates and ropes

polychloroethenewater pipes and insulation on electricity cables

Polymer problemsOne of the useful properties of polymers is that they are unreactive, so they are suitable for storing food and chemicals safely. Unfortunately, this property makes it difficult to dispose of polymers.Complete combustionComplete combustion needs a plentiful supply of air so that the elements in the fuel react fully with oxygen.Fuels such as natural gas and petrol contain hydrocarbons. These are compounds of hydrogen and carbon only. When they burn completely: the carbon oxidises to carbon dioxide the hydrogen oxidises to water (remember that water, H2O, is an oxide of hydrogen).In general, for complete combustion:hydrocarbon + oxygen carbon dioxide + water Here are the equations for the complete combustion of propane, used in bottled gas:propane + oxygen carbon dioxide + waterC3H8 + 5O2 3CO2 + 4H2OIncomplete combustionIncomplete combustion occurs when the supply of air or oxygen is poor. Water is still produced, but carbon monoxide and carbon are produced instead of carbon dioxide.In general for incomplete combustion:hydrocarbon + oxygen carbon monoxide + carbon + water The carbon is released as soot. Carbon monoxide is a poisonous gas, which is one reason why complete combustion is preferred to incomplete combustion. Gas fires and boilers must be serviced regularly to ensure they do not produce carbon monoxide. The Bunsen burnerThe Bunsen burner is commonly used in school laboratories to heat chemicals. Its fuel is natural gas, which is almost pure methane, CH4. Methane is a hydrocarbon. So the Bunsen burner has an air hole that allows complete or incomplete combustion.Air hole openWhen the air hole is open, air is drawn into the chimney, where it mixes with the natural gas. This ensures complete combustion:methane + oxygen carbon dioxide + water A very hot, blue flame is produced.

The hottest part of the flame is at the tip of the dark blue coneAir hole closedWhen the air hole is closed the natural gas can only mix with air at the mouth of the chimney. Incomplete combustion occurs as a result:methane + oxygen carbon monoxide + carbon + water

The yellow flame is often called the safety flameA yellow flame is produced, which transfers less heat energy than the blue flame. The yellow flame is brighter than the blue flame because the specks of carbon glow when heated.Formulas of the possible combustion products from hydrocarbon fuelsnameformulaformed in complete combustionformed in incomplete combustion

carbon dioxideCO2yes

carbon monoxideCOyes

sootCyes

waterH2Oyesyes

Some of the common air pollutants and how they are formedpollutanthow it is formed

carbon monoxideincomplete combustion of the fuel in car engines

oxides of nitrogen, NOxformed from the heat and pressures found in a car engine

sulfur dioxidesulfur impurities in the fuel burn

Water vapour went down because: as the Earth cooled down, most of the water vapour condensed and formed the oceans.Carbon dioxide went down because: it was absorbed by plants during photosynthesis it was locked up in fossil fuels it dissolved in the oceans.Nitrogen went up because: it is not very reactive and, once formed, it is not easily removed from the atmosphere again. Oxygen went up because: it was released by plants during photosynthesisWaterproof clothingNylon has some desirable properties. It does not let ultraviolet light pass through it, and it is: tough lightweight waterproof.Unfortunately, nylon does not let water vapour pass through it either. This means nylon waterproof clothing traps sweat, so that after a while the inside of the clothing becomes wet and unpleasant to wear.Gore-TexGore-Tex has the desirable properties of nylon, but is also 'breathable'. It lets water vapour from sweat pass to the outside, but it stops rain drops from passing to the inside. Clothing made of Gore-Tex is very useful to hikers and other people who work or play outside.The construction of Gore-Tex- Higher tierTeflon is the trade name for a polymer called polytetrafluoroethene, or PTFE. It is very slippery, so is used to make non-stick coatings for pans. It is also used in Gore-Tex.Types of food additivestype of additivereason for adding it

antioxidantsstop food from reacting with oxygen

colouringsimprove the colour of food

flavour enhancersimprove the flavour of food

emulsifiershelp oil and water mix, and not separate out

Additives with an E number have been licensed by the European Union. Some are natural, some artificial, but they have all been safety tested and passed for use.Baking powderBaking powder is used for baking cakes. It contains sodium hydrogencarbonate, which breaks down when heated to form carbon dioxide gas. The carbon dioxide helps to make the cake mixture rise, so that it is light and fluffy.Here are the equations for the reaction:sodium hydrogencarbonate sodium carbonate + carbon dioxide + water2NaHCO3 Na2CO3 + CO2 + H2OSummary of the properties of perfumepropertywhy the property is important

non-toxicdoes not poison the wearer

does not irritate the skinprevents the wearer from suffering rashes

evaporates easily - very volatileperfume molecules reach the nose easily

insoluble in waterit is not washed off easily

does not react with wateravoids the perfume reacting with perspiration

Volatility - Higher tierVolatile liquids evaporate easily. They readily change from a liquid to a gas. This is because there are only weak attractive forces between particles in the substance. These forces are overcome easily, so particles with enough energy can escape from the liquid.EstersEsters are chemicals with pleasant smells. They are used in perfumes, and as solvents.Making estersEsters occur naturally, but can be made in the laboratory by reacting an alcohol with an organic acid. A little sulfuric acid is needed as a catalyst. This is the general word equation for the reaction:alcohol + organic acid ester + waterFor example:methanol + butanoic acid methyl butanoate + waterThe diagram shows how this happens, and where the water comes from:

Making estersWhat esters smell likeDifferent esters have different smells.alcoholorganic acidester madesmell of ester

pentanolethanoic acidpentyl ethanoatepears

octanolethanoic acidoctyl ethanoatebananas

pentanolbutanoic acidpentyl butanoatestrawberries

methanolbutanoic acidmethyl butanoatepineapples

Page: 1. 12. 23. 3PaintsPaints are used to decorate surfaces or protect them from damage. A pigment is a coloured substance used in paint. Paints contain these ingredients: a pigment - gives the paint its colour a binding medium - a liquid polymer that hardens to form a continuous layer when the paint dries a solvent - dissolves the binding medium and makes the paint more fluid.RocksThe materials used in the construction industry include: aluminium and iron - metals obtained from ores brick - made from clay glass - made from sand cement and concrete - made using limestone granite, limestone and marble - rocks mined or quarried from the ground.Granite is much harder than marble, which is much harder than limestone.A summary of three common alloys, the metals they contain, and their typical usesalloymain metal(s) in alloytypical use

amalgammercurydental fillings

brasscopper and zincmusical instruments, coins, door knockers

solderlead and tinjoining electrical wires and components

Iron versus aluminiumIron and aluminium are used to build cars. They are both malleable - they can be bent or pressed into shape. The table summarises some differences in their properties. A summary of the differences between iron and aluminiumpropertyironaluminium

densityhighlow

magnetic?yesno

corrodes easily?yesno

The main materials used in the manufacture of carsmaterialtypical usereason for use

steelbody panels and chassisstrong and malleable

copperelectrical wiringgood conductor of electricity

aluminiumbody panels and interior fittingslightweight and rust-proof

glasswindowstransparent

plasticsbody panels, lights and dashboardtough and easily moulded to desired shape

fibresseats and carpetsgood heat insulators, and can be woven into fabrics

The Haber processThe raw materials for this process are hydrogen and nitrogen: hydrogen is obtained by reacting natural gas with steam, or from cracking oil fractions nitrogen is obtained from the air.Air is 78 per cent nitrogen and nearly all the rest is oxygen. When hydrogen is burned in air, the oxygen combines with the hydrogen, leaving nitrogen behind.In the Haber process, nitrogen and hydrogen react together under these conditions: a high temperature - about 450C a high pressure an iron catalyst.In addition, any unreacted nitrogen and hydrogen are recycled.The reaction is reversible. In a chemical equation, the symbol is used instead of an ordinary arrow if the reaction is reversion:nitrogen + hydrogen ammoniaN2 + 3H2 2NH3The flow chart shows the main stages in the Haber process.

The Haber process for making ammoniaManufacturing costsDifferent factors affect the cost of making a new substance.Factors that increase cost include: high pressures (they increase the cost of the equipment) high temperatures (they increase the energy costs). Factors that decrease catalysts (they increase the rate of reaction) recycling unreacted starting materials automating equipment (because fewer people need to be employed, cutting the wage bill).The pH scalepHexample substance

strong acidic0battery acid

1stomach acid

2lemon juice

3vinegar

4acid rain

5black coffee

6saliva

neutral7pure water

8sea water

9baking powder

10milk of magnesia

11ammonia

12soapy water

13bleach

strongly alkaline14drain cleaner

Page: 1. 12. 23. 34. 45. Examples of fertilisers, their formula and the essential elementsfertiliserformulaessential elements

ammonium nitrateNH4NO3nitrogen

ammonium sulfate(NH4)2SO4nitrogen

ammonium phosphate(NH4)3PO4nitrogen and phosphorus

potassium nitrateKNO3potassium and nitrogen

urea(NH2)2COnitrogen

Making a fertiliser in the labThe preparation of a fertiliser in a lab involves the following equipment: a measuring cylinder to measure a particular volume of an alkali solution a burette to add acid a little at a time until the alkali has been neutralised a filter funnel to remove solid crystals of fertiliser after evaporating some of the water from the neutral fertiliser solution. Eutrophication A major problem with the use of fertilisers occurs when they are washed off the land by rainwater into rivers and lakes. The increase of nitrate or phosphate in the water encourages the growth of algae. The algae form a bloom over the water surface. This prevents sunlight reaching other water plants, which then die. Bacteria break down the dead plants and as they respire these bacteria use up the oxygen in the water causing most other living organisms to die. Nitrates or phosphates from fertilisers can cause eutrophication in water Preparation of a fertiliser Synthetic fertilisers are prepared in the lab by the reaction of an acid with an alkali. A quantity of alkali is placed in a beaker and a solution of acid is run in until the solution is neutral. This can be measured with a pH meter or by removing samples for testing with universal indicator. The neutral solution of salt is evaporated until crystals form. These are filtered out, washed and dried in a warm oven. Products from sodium chlorideThe products of the electrolysis of sodium chloride solution have important uses in the chemical industry.HydrogenHydrogen is used in the manufacture of ammonia and margarine (it is used to harden vegetable oils).ChlorineChlorine is used to: kill bacteria in drinking water and swimming pool water make solvents make plastics such as polyvinyl chloride (PVC) make household bleach.Sodium hydroxideSodium hydroxide is used to make soap and household bleach.BleachHousehold bleach, sodium chlorate, is made when sodium hydroxide and chlorine react together:sodium hydroxide + chlorine sodium chloride + water + sodium chlorate2NaOH + Cl2 NaCl + H2O + NaClOHousehold bleach is used to clean and disinfect toilets, drains and kitchen surfaces.Reducing carbon dioxide in the airOne way to reduce the amount of carbon dioxide in the air is to burn less fossil fuels. Unfortunately, we depend on the burning of fossil fuels for heating, electricity generation and transport. If we are to burn less fossil fuels, we will need alternatives for these essential activities.Benefits and problems of using fossil fuels for motor vehiclesbenefitsproblems

biofuelrenewablemade from plants that absorb carbon dioxide as they growstill releases carbon dioxide when burnt-more land needed to grow sufficient amounts of plants to use for fuel

electricitydo not produce waste gases when usedoften comes from power stations that burn fossil fuelsshort range before needing to be rechargedrecharging takes a long time

Use of nanoparticlesNanoparticles are used in products that are currently available. sports equipment: nanoparticles are added to materials to make them stronger whilst often being lighter. They have been used in tennis rackets, golf clubs and shoes clothing: silver nanoparticles have been added to socks. This stops them from absorbing the smell of sweaty feet as the nanoparticles have antibacterial properties healthcare: nanoparticles are used in sunscreens. They offer protection and can be rubbed in so there are no white marks.Harmful effectsThere are some concerns that nanoparticles may be toxic to people. They may be able to enter the brain from the bloodstream and cause harm. Some people think more tests should take place before nanoparticles of a material are used on a wider scale. Properties and uses of nanoparticlesNanoparticles have a very large surface area compared with their volume, so they are often able to react very quickly. This makes them useful as catalysts to speed up reactions. They can, for example, be used in self-cleaning ovens and windows.Nanoparticles also have different properties to the same substance in normal-sized pieces. For example, titanium dioxide is a white solid used in house paint and certain sweet-coated chocolates. Titanium dioxide nanoparticles are so small that they do not reflect visible light, so cannot be seen. They are used in sun screens to block harmful ultraviolet light without appearing white on the skin.In addition to new cosmetics such as sun screens and deodorants, nanoscience may lead to the development of: New catalysts New coatings New computers Stronger and lighter building materials Sensors that detect individual substances in tiny amountsChanging concentration or pressureIf the concentration of a dissolved reactant is increased, or the pressure of a reacting gas is increased: There are more reactant particles in the same volume There is a greater chance of the particles colliding The rate of reaction increasesChanging particle sizeIf a solid reactant is broken into small pieces or ground into a powder: Its surface area is increased More particles are exposed to the other reactant There is a greater chance of the particles colliding The rate of reaction increasesChanging the temperatureIf the temperature is increased: The reactant particles move more quickly More particles have the activation energy or greater The particles collide more often, and more of the collisions result in a reaction The rate of reaction increasesUsing a catalystCatalysts increase the rate of reaction without being used up. They do this by lowering the activation energy needed. With a catalyst, more collisions result in a reaction, so the rate of reaction increases. Different reactions need different catalysts.Catalysts are important in industry because they reduce costs.Aluminium extractionAluminium is the most abundant (found in large quantities) metal on Earth. But it is expensive, largely because of the amount of electricity used up in the extraction process.Aluminium ore is called bauxite. The bauxite is purified to yield a white powder - aluminium oxide - from which aluminium can be extracted.The extraction is done by electrolysis. But first the aluminium oxide must be melted so that electricity can pass through it. Aluminium oxide has a very high melting point (over 2000C) so it would be expensive to melt it. Instead, it is dissolved in moltencryolite - an aluminium compound with a lower melting point than aluminium oxide. The use of cryolite reduces some of the energy costs involved in extracting aluminium.

The diagram shows an aluminium oxide electrolysis tank. Both the negative electrode (cathode) and positive electrode (anode) are made of graphite, a form of carbon.Aluminium metal forms at the negative electrode and sinks to the bottom of the tank, where it is tapped off.Oxygen forms at the positive electrodes. This oxygen reacts with the carbon of the positive electrodes, forming carbon dioxide, and they gradually burn away. As a result, the positive electrodes have to be replaced frequently. This adds to the cost of the process.Page: 1. 12. 23. 34. 45. 56. 61. Back2. NextBack to Electrolysis indexProperties of ionic compounds High melting and boiling points - Ionic bonds are very strong - a lot of energy is needed to break them. So ionic compounds have high melting and boiling points. Conductive when liquid - Ions are charged particles, but ionic compounds can only conduct electricity if their ions are free to move. Ionic compounds do not conduct electricity when they are solid - only when dissolved in water or melted.Properties of ionic compoundsIonic compoundProperties

Sodium chloride, NaClHigh melting point: 800CNon-conductive in its solid state, but when dissolved in water or molten NaCl will conduct electricity.

Magnesium oxide, MgOHigher melting point than sodium chloride: around 2,800C. This is because its Mg2+ and O2- ions have a greater number of charges, so they form stronger ionic bonds than the Na+ and Cl- ions in sodium chloride.Because magnesium oxide stays solid at such high temperatures, it remains non-conductive. It is used for high-temperature electrical insulation.

Soluble and insoluble saltsSolubleInsoluble

All nitratesNone

Most sulfatesLead sulfate, barium sulfate and calcium sulfate

Most chlorides, bromides and iodidesSilver chloride, silver bromide, silver iodide, lead chloride, lead bromide, lead iodide

Sodium carbonate, potassium carbonate, ammonium carbonateMost other carbonates

Sodium hydroxide, potassium hydroxide, ammonium hydroxideMost other hydroxides

Making an insoluble saltYou can see from the table above that silver chloride is insoluble. To make it, you need a soluble silver salt and a soluble chloride salt. Silver nitrate and sodium chloride are both soluble. When mixing their solutions together, the result is insoluble silver chloride and soluble sodium nitrate.The silver chloride appears as tiny particles suspended in the reaction mixture: it forms a precipitate. The precipitate can be filtered, washed with water on the filter paper and then dried in an oven.Here are the word and balanced formulae equations for the reaction:silver nitrate (soluble) + sodium chloride (soluble) silver chloride (insoluble) + sodium nitrate (soluble)AgNO3 + NaCl AgCl + NaNO3Uses of insoluble salts

Barium is used to emphasize organs in x-raysBarium sulfate is an example of an insoluble salt. It is used with patients in order to help diagnose problems with the intestine. Like bone and metal, barium sulfate shows up on an x-ray. A 'barium meal' is given to a patient and they are then x-rayed. The barium sulfate will show up the shapes of the intestine. Doctors can then tell if there are any problems such as growths or lumps.Barium sulfate is toxic but it is safe to use because it is insoluble (does not dissolve). This prevents it from entering the blood.Flame testsMetals change the colour of a flame when they are heated in it. Different metals give different colours to the flame, so flame tests can be used to identify the presence of a particular metal in a sample. This is how you would carry out a typical flame test:1. Dip a clean flame test loop in the sample solution2. Hold the flame test loop at the edge of a Bunsen burner flame3. Observe the changed colour of the flame, and decide which metal it indicates4. Clean the loop in acid and rinse with water, then repeat steps 1 to 3 with a new sampleDifferent coloursSome common metals and their flame test coloursMetalFlame test colour

BariumPale green

CalciumYellow-red

CopperGreen-blue

LithiumRed

SodiumOrange

PotassiumLilac

ExampleFlame tests are useful for confirming the results of a precipitate test. For example, an unknown solution that produced a pale blue precipitate with sodium hydroxide solution, and a green-blue flame test, must contain a copper compound.To identify an alkali metal, a flame test must be used instead of a sodium hydroxide precipitate test. This is because the alkali metals do not form precipitates with sodium hydroxide.Testing for halide ions

A test using silver nitrateThe halogens are the elements in group 7 of the periodic table, like chlorine, bromine and iodine. Their ions are called halide ions.You can test to see if a solution contains chloride, bromide or iodide ions by using silver nitrate. If silver nitrate solution is added to a sample of water containing halide ions the silver halide is precipitated. This is because the silver halides are all insoluble in water.The results look like this: Silver chloride is a white precipitate Silver bromide is a cream precipitate Silver iodide is a pale yellow precipitateFractional distillation of liquid airYou need to be able to explain how nitrogen and oxygen are obtained from the air.About 78 per cent of the air is nitrogen and 21 per cent is oxygen. These two gases can be separated by fractional distillation of liquid air.Liquefying the air

Fractional distillationAir is filtered to remove dust, and then cooled in stages until it reaches 200C. At this temperature it is a liquid. We say that the air has been liquefied. Here's what happens as the air liquefies:1. Water vapour condenses, and is removed using absorbent filters2. Carbon dioxide freezes at 79C, and is removed3. Oxygen liquefies at 183C4. Nitrogen liquefies at 196CThe liquid nitrogen and oxygen are then separated by fractional distillation.Properties of the groups: Alkali metals are reactive, soft metals with low densities Transition metals are unreactive and many have everyday uses Halogens are reactive non-metals that form coloured vapours Noble gases are unreactive non-metals. All gases fall in to this category Bonding summary Type of bondIonicSimple covalentGiant covalentMetallic

How the bond is formedIons formed between a metal and a non-metalShared pair of electrons between non-metalsShared pair of electrons between non-metals forming a giant structureFormed between metals. Has a 'sea' of delocalised electrons

ExampleSodium chlorideBromine, waterDiamondCopper

Diagram

Melting and boiling pointsHighLowHighUsually high - except mercury

SolubilityMany dissolveSome dissolveInsolubleInsoluble

Conduc- tivity of elec- tricityConducts as a liquid or in solution. Does not conduct as a solidDo not conductMost do not conduct except graphite and buckminster- fullereneConducts as a solid or a liquid

Why does the reactivity increase down the group? Higher tierAll alkali metals have one electron in the outer shell. In a reaction, this electron is lost and the alkali metal forms a +1 ion. As you go down group 1, the number of electron shells increases lithium has two, sodium has three etc. Therefore, the outermost electron gets further from the nucleus. The attraction from the positive nucleus to the negative electron is less. This makes it easier to remove the electron and makes the atom more reactive.Exothermic reactionsThese are reactions that transfer energy to the surroundings. The energy is usually transferred as heat energy, causing the reaction mixture and its surroundings to become hotter. The temperature increase can be detected using a thermometer. Some examples of exothermic reactions are: Burning (combustion) Neutralisation reactions between acids and alkalis The reaction between water and calcium oxide ExplosionsEndothermic reactionsThese are reactions that take in energy from the surroundings. The energy is usually transferred as heat energy, causing the reaction mixture and its surroundings to get colder. The temperature decrease can also be detected using a thermometer. Some examples of endothermic reactions are: Electrolysis The reaction between ethanoic acid and sodium carbonate Photosynthesis The reaction between ammonium nitrate and water The thermal decomposition of calcium carbonate in a blast furnaceFactors affecting the rates of reactionYou will be expected to remember the factors that affect the rate of reactions, and to plot or interpret graphs from rate experiments.How to increase the rate of a reactionThe rate of a reaction increases if: The temperature is increased The concentration of a dissolved reactant is increased The pressure of a reacting gas is increased Solid reactants are broken into smaller pieces A catalyst is used

Rate of reaction and changing conditionsExplaining lossesFew reactions give a 100 per cent yield. The reasons that this happens are: Incomplete reactions not all reactions completely finish Losses during the practical Unwanted by-products being producedEffect of temperatureThe rate of a chemical reaction can be changed by altering the temperature. If the temperature is increased: The reactant particles move more quickly They have more energy The particles collide more often, and more of the collisions are successful The rate of reaction increasesEffect of concentration and pressureThe rate of a chemical reaction can be changed by altering the concentration of a reactant in solution, or the pressure of a gaseous reactant. If the concentration or pressure is increased: The reactant particles become more crowded There is a greater chance of the particles colliding The rate of reaction increasesEffect of surface areaThe rate of a chemical reaction can be raised by increasing the surface area of a solid reactant. This is done by cutting the substance into small pieces, or by grinding it into a powder. If the surface area of a reactant is increased: More particles are exposed to the other reactant There are more collisions The rate of reaction increases Explosions An explosion is a very fast reaction which releases a large volume of gaseous products. There is a danger of explosion in factories that handle powdered flammable substances. These substances include custard powder, flour and powdered sulfur. CatalystReaction catalysed

IronMaking ammonia from nitrogen and hydrogen

PlatinumMaking nitric acid from ammonia

Vanadium(V) oxideMaking sulfuric acid

CalorimetryMeasuring heat transfers is called calorimetry. The diagram shows a simple calorimetry experiment to measure the heat energy released from burning fuel. You should be able to recognise and label apparatus like this:

CalorimetryIn a typical calorimetry experiment:1. Cold water is measured into a copper calorimeter - a small metal can2. The starting temperature of the water is recorded3. The water is heated using the flame from the burning fuel4. The final temperature of the water is recordedThe spirit burner containing the fuel is usually weighed before and after the experiment. In this way, the mass of the fuel burned can be found.Fair testingWhen comparing different fuels, it is important to carry out a fair test. Several variables should be kept constant, including: The mass - or volume - of water used The starting temperature of the water The temperature increase The distance of the flame from the calorimeterMore reliable results can be obtained by repeating the experiment many times. The biggest source of error in calorimetry is usually unwanted heat loss to the surroundings. This can be reduced by insulating the sides of the calorimeter and adding a lid.Comparing processes - Higher tierYou should be able to evaluate the advantages and disadvantages of each type of process, given relevant information. The table summarises some of the advantages and disadvantages of continuous and batch processes.FactorContinuousBatch

Cost of factory equipmentHighLow

Rate of productionHighLow

Shut-down timesRareOften

WorkforceFew people neededMany people needed

Ease of automationRelatively easyRelatively difficult

Examples of displacement reactionsHalogenMetal halideThe most reactive halogenReaction

ChlorineSodium bromideChlorineChlorine + sodium bromide sodium chloride + bromine

ChlorineSodium iodideChlorineChlorine + sodium iodide sodium chloride + iodine

BromineSodium chlorideChlorineNo reaction

BromineSodium iodideBromineBromine + sodium iodide sodium bromide + iodine

IodineSodium chlorideChlorineNo reaction

IodineSodium bromideBromineNo reaction

The compounds of transition metals are often coloured. Copper compounds are blue Iron(II) compounds are light green Iron(III) compounds are orange/brown Iron is a catalyst in the Haber process Nickel is a catalyst used in the manufacture of margarine

Superconductors

Maglev trains are held just above the tracks by powerful superconducting electromagnets.At low temperatures, some metals can become superconductors. They will have little or no electrical resistance. For example, mercury is a liquid metal. It solidifies at 38.8 C and becomes a superconductor at 268.8 C.Superconductors have potential benefits, including: Power transmission without losses Super-fast electronic circuits Powerful electromagnetsSuperconducting electromagnets are used in hospital MRI scanners for example.Drawbacks - Higher tierAt the moment, superconductors only work at very low temperatures. They have to be kept very cold with liquid nitrogen or liquid helium. A lot of work is going into developing superconductors that will work at normal temperatures. Until this happens, their uses will be limited.Water - Higher tierSome soluble substances are not removed by the treatment processes. For example, nitrate fertilisers applied to farmland may be washed into rivers and lakes. Nitrates can be poisonous, particularly for young people or if they are in high concentrations, so care has to be taken to limit nitrates getting into water sources.Distillation of sea waterIn principle, distillation can be used to make large volumes of fresh water from sea water. However, it takes a lot of energy to boil water for this process. This would make the fresh water produced much more expensive than water from traditional sources. In addition, there are problems disposing of the salt-rich waste water left over by the process. However, distillation is used in hot countries such as Saudi Arabia.The benefits and drawbacks of hard waterYou need to be able to evaluate the environmental, social and economic aspects of water hardness.Hard water has some benefits compared to soft water. For example, the dissolved calcium compounds in hard water: can improve the taste of the water are good for the development and maintenance of bones and teeth can help to reduce heart diseaseBut hard water also has some drawbacks compared to soft water. For example: More soap is needed to produce lather, which increases costs. This happens with temporary or permanent hardness. The scum produced is unsightly - spoiling the appearance of baths and shower screens, for example. Temporary hardness can reduce the efficiency of kettles and heating systems. This is because limescale (a solid containing calcium carbonate) is produced when the water is heated. It coats the heating element in kettles, and the inside of boilers and hot water pipes. This means more energy is needed to heat the water, again increasing costs. Pipes may become blocked by limescale - causing the heating system to break down.Softening hard waterThe damaging effect that hard water can have means that it may be beneficial to soften the water. Methods for softening hard water involve the removal of calcium ions and magnesium ions from the water.There are two methods for softening hard water: adding sodium carbonate to the water using ion exchange columnsWATER PURIFICATIONThe water is then passed into a sedimentation tank. Aluminium sulfate is added to clump tiny particles together to make larger particles, which settle out more easily. The water is then passed through a fine filter, such as carbon granules, to remove very small particles.

Water is purified by filtration, sedimentation and the addition of chlorineChlorinating the waterChlorine is added to drinking water to sterilise it. The chlorine kills microbes - including microbes that cause potentially-fatal diseases such as typhoid, cholera and dysentery.Testing water purityThe purity of water can be tested by: measuring its boiling point evaporating it (to dryness) on an evaporating dishPure water boils at 100C, but its boiling point increases as the concentration of dissolved salts increases.Pure water will leave no solids behind when it is evaporated, whereas impure water will leave solids behind on the evaporating dish.AMMONIA AND HABER PROCESSStages of the Haber process

Part of the equipment used in the Haber processStage 1Having obtained the hydrogen and nitrogen gases (from natural gas and the air respectively), they are pumped into the compressor through pipes.

Stage 2The gases are pressurised to about 200 atmospheres of pressure inside the compressor.

Stage 3The pressurised gases are pumped into a tank containing beds of iron catalyst at about 450C. In these conditions, some of the hydrogen and nitrogen will react to form ammonia.

Stage 4The unreacted nitrogen and hydrogen, together with the ammonia, pass into a cooling tank. The cooling tank liquefies the ammonia, which can be removed into pressurised storage vessels.

Stage 5 The unreacted hydrogen and nitrogen gases are recycled by being fed back through pipes to pass through the hot iron catalyst beds again.

Read on if you're taking the higher paper. Page 1 2 3 4BackNextBackNextProperties of methanol, ethanol and propanolThe alcohols methanol, ethanol and propanol all have the following properties:1. They are colourless liquids that dissolve in water to form a neutral solution (pH7).2. They react with sodium to produce hydrogen and a salt. For example:ethanol + sodium hydrogen + sodium ethoxideThis reaction is similar but less vigorous to the reaction of water with sodium. This is due to the similarity in structure between water and the OH group in alcohols.3. They burn in the air, releasing energy and producing carbon dioxide and water.Properties of carboxylic acidsCarboxylic acids have the following properties:1. They dissolve in water to produce acidic solutions (pH less than 7).2. They react with carbonates to produce carbon dioxide and a salt and water. For example:calcium carbonate + ethanoic acid calcium ethanoate + water + carbon dioxide3. They all react with alcohols, in the presence of an acid catalyst, to form esters. For example:ethanol + ethanoic acid ethyl ethanoate + waterHere are three examples:Name of alcoholName of carboxylic acidName of ester

EthanolPropanoic acidEthyl propanoate

ButanolMethanoic acidButyl methanoate

PentanolEthanoic acidPentyl ethanoate

Some common transition metals and the colours of their precipitatesTransition metal ion Colour of precipitate

Al3+white

Ca2+white

Cu2+blue

Fe2+green

Fe3+brown

Comparing methods of ethanol productionFermentation of carbohydratesReacting ethene with steam

AdvantagesDisadvantagesAdvantagesDisadvantages

Renewable (uses available crops)Large areas of land neededLess land neededNon-renewable (uses crude oil)

Low amounts of energy neededCarbon dioxide is produced as a by-productNo by-productsHigher amounts of energy needed

Little technology neededSlow processFast processMore technology needed

Ethanol produced by fermentation of carbohydrates also only produces a low concentration of ethanol. Further processing (known as distillation) is often needed.Properties of esters They are soluble (dissolve) in organic solvents. They are also good solvents. They range from colourless, volatile liquids to waxy solids. They have strong odours. Their solubility in water decreases as their chains become longer (possess more carbon atoms).Uses of esters Some esters are used in perfumes due to their strong, pleasant smell. Some are used as fruit flavourings in cooking ingredients. Some are used in cosmetics.Making ethanol Higher tierThe table below summarises of some of the advantages and disadvantages of making ethanol by fermentation or by hydration of ethene.Feature of processFermentationHydration of ethene

Conditions usedwarm, normal pressurehigh temperature, high pressure

Type of processbatch (stop-start)continuous (runs all the time)

Sustainabilityuses renewable resources (glucose from plants)uses non-renewable resources (ethene from crude oil)

Purificationlow purity needs fractional distillationhigh purity no by-products are made

Percentage yieldlow about 15%high around 100%

Atom economymedium 51%maximum 100%

Which method of making ethanol is the best? Both have pros and cons although the method using the hydration of ethane can be run continuously, there are no by-products, and it produces a much higher percentage yield. But, in fact, the vast majority of the worlds ethanol is made by fermentation.Alcohols Higher tierThe general formula for alcohols is CnH2n + 1OH, where n is the number of carbon atoms. For example, butanol contains four carbon atoms. Its molecular formula is C4H9OH.The table below shows the names, molecular formulae and displayed formulae for alcohols containing up to five carbon atoms. Number of C atomsName of alcoholMolecular formulaDisplayed formula

1methanolCH3OH

2ethanolC2H5OH

3propanolC3H7OH

4butanolC4H9OH

5pentanolC5H11OH

Testing for unsaturationOrange bromine water can be used to test for unsaturation. When it is added to a sample of the fat or oil: the bromine water stays orange with a saturated fat or oil the bromine water goes colourless with an unsaturated fat or oilThis is similar to the test for alkenes (which are unsaturated).An addition reaction Higher tierBromine Br2 can also be used to test for unsaturation. An addition reaction happens at the carbon-carbon double bond, producing a dibromo compound. This is colourless, so the observed change is that the bromine is decolourised.The Test for Water Vapour (Steam), H2O(g).1) Water vapour has no colour or smell.2) Water vapour has no effect on moist litmus paper or moist universal indicator paper - it is neutral.3) Water vapour puts out a lit splint.Specific Tests for Water or Water Vapour.1) Water or its vapour will turn cobalt chloride paper from blue to pink.2)Water or its vapour turnsanhydrous copper(II) sulfate crystals from white to blue.3)Water melts at 0C and boils at 100 C.