Topic 1 Chemical Reactions

1. In a chemical reaction a ....................... substance is formed. A chemical reaction can be identified by

a ............................................ change a ............................................ being formed (effervescence) a ............................................ being formed (precipitate) an ............................................ change (e.g. heat and .............................)

2. All of the elements are listed in the ............................................ ............................................ . Each element has its own symbol.

Symbol Element Ag Cu

sodiumoxygen

3. Compounds are made when .......................... or more elements join together. Compounds with names ending in –ide usually only contain only .......................... elements. Compounds with names ending in –ite or –ate also contain the element ...................................... .

4. The substances in a mixture are not chemically ............................... together and can easily be separated.

Substances Method of separationA solid and a liquidA mixture of liquids

5. When a solid (e.g. salt) is dissolved in a liquid (e.g water) a ................................. of salt and water is formed. The liquid (water) is called the .................................. and the solid (salt) is celled the ..................................... . Solutions in water are called ................................... solutions. The solution becomes ....................................... when no more solid can be dissolved. The concentration of a solution is a measure of how much solute is dissolved in the solvent. If the amount of solute dissolved is large it is a ....................................... solution. Small amounts of solute dissolved form . ...................................... solutions.

Topic 2 Speed of Reactions

1. The speed of a reaction can be speeded up using four methods

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using a .............................................. increasing the ......................................... increasing the .......................................... of a solution increasing the ........................................ area of a solid by using ..................................

particles.

2. A ................................... speeds up a reaction but is not used up in the reaction.Catalyst Used in making

AmmoniaPlatinum

Most cars now have catalytic ...................................... to turn ...................................... exhaust gases into less harmful gases.

3. For a fair comparison of two experiments only .......................... variable can be changed at a time. Three examples of variables are

concentration of reactants .................................................... ....................................................

4. A word equation describes what happens in a chemical reaction e.g. Magnesium and chlorine are the ............................................. Magnesium chloride is the ........................................ The “+” means ............................................................................. The arrow means .........................................................................

Topic 3 Atoms and the Periodic Table1. Information on elements can be found in the Periodic Table. There are eight groups of elements and some are given special names. Elements in the same group have ……..……………………………. chemical properties.

Group Name of group First two elements Properties of elements number in this group in this group

1 very reactive metals7 Halogens

2

8 Helium, Neon

The metals in the centre of the Periodic Table between groups 2 and 3 are called the ........................................... metals. Elements can be classified in different ways eg (i) Solids, liquids and ……………………………. There are only two liquid elements …………………………. and ………………..……..… (ii) Naturally occurring or made by scientists. An example of an element made by scientists is ………………………… (iii) Metal or ……………. - ……………………….2. Information about the different particles found in an atom of an element is summarised in this table.

Particle Mass (amu) Charge Position in atomProton 1Neutron inside the nucleusElectron 1-

3. For an atom to be neutral the number of protons and electrons are ................................. . The atomic number of an element is the number of ................................ in an atom of the element. The .......................... number of an element is the number of protons + the number of .................................... in an atom of the element. The relative atomic mass of an element is the ...................................... mass of all its atoms. The electrons in an atom are arranged in energy ……………………………………4. Information on atoms of different elements can be show in a table.

Element Symbol Atomic No. Mass No. Protons Neutrons Electrons Electron ArrangementGroup No

Ca

4020Ca

4020Ca

F

199F

199F

5. Isotopes are atoms with the same ………………………………. number but different …………………………. number.

Topic 4 How Atoms Combine

1. A covalent bond joining two ..................................... atoms is formed by the sharing of two ................................ . A group of atoms joined in this way is called a ........................................... . Some elements contain two

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atoms joined by a covalent bond. These elements form two atom (...........................................) molecules. The elements which form diatomic molecules are iodine (I2), bromine(............),.................................. (Cl2), ........................................ ( ............), ........................................ ( ............), ........................................ ( ............), and hydrogen (H2) (Remember the ‘genuine’ rule).

2. In a covalent bond two positive nuclei are held together by their attraction for the ……………………………… pair of electrons.

3. We can use valencies to work out the chemical formula of a compound. e.g. sodium chloride NaCl calcium bromide ......................

potassium oxide ...................... aluminium nitride ......................

4. Sometimes we can work out the formula of a compound from its name. When this is the case we do not use valency. The name of the compound contains a prefix which tells us how many atoms of each element are present.

e.g. carbon monoxide CO carbon dioxide ......................sulphur trioxide ...................... dinitrogen monoxide ......................

5. When a compound contains a transition metal a Roman numeral is used to show the metal’s valency number. e.g. iron(III) chloride FeCl3 copper(I) oxide ......................

iron(III) sulphide ...................... vanadium(V) oxide ......................

6. The structural formula for an element or a compound shows all of the atoms and its covalent bonds. We can show the shape of the molecule. e.g. ammonia NH3 H-N-H N

H H H H

Methane CH4

Water H2O

Topic 5 Fuels

1. A ............................... is a chemical which gives out energy when it burns. Burning is also called ............................................ . When a fuel burns it combines with ........................................ from the air to form an oxide. Burning is an ........................................ reaction as it gives out energy.

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The test for oxygen is that it ………………….…………………….. a glowing splint. Oxygen makes up about ………. % of r the air with nitrogen making up most of the remaining ………… %

2. The fossil fuels are ........................................, ........................................ and natural gas. Crude oil and natural gas are mixtures of compounds called .............................................. . Hydrocarbons contain only the elements ........................................ and ........................................ . Because fossil fuels will run out one day they are called ........................................ resources. Crude oil is separated into different fractions by fractional ................................................... . This works because the different fractions have different ........................................ points.

3. Score out the incorrect words.Coal was formed when plants/sea organisms died and were buried underground.After thousands/millions of years heat and pressure changed the material into a finite/renewable resource.

Oil and natural gas formed when plants/sea organisms died and were buried underground.After thousands/millions of years heat and pressure changed the material into a finite/renewable resource.

4. Crude oil is separated into fractions in an oil refinery. The fractions have molecules which contain different numbers of carbon atoms.

Of these fractions the ....................................... fraction is the most flammable.

The ........................................ fraction is the most viscous (thick and sticky).5

Fraction Number of carbon Use ofname atoms per molecule fraction

refinery gas 1-4 bottled gas

gasoline 5-12...............................

kerosene 9-16..............................

diesel 13-25..............................

fuel oil 25-70...............................

residue more than 70 ..............................

The greater the number of carbon atoms in the molecule the .................................... the boiling point of the fraction.

5. Hydrocarbons burn in a plentiful supply of air to produce ................................................ ................................... and .......................................... . The test for carbon dioxide is that it turns ......................... ....................................... milky (or chalky).

6. Carbon (soot) and the very poisonous gas, ................................... ........................................... (CO) are produced when hydrocarbons burn in a limited .................... supply.

7. ........................................ and ...................................... from the air react inside a car engine to form oxides of nitrogen which are poisonous gases.

8. The burning of some fuels containing sulphur releases .................................. ................................... (SO2), a poisonous gas, into the atmosphere.

9. Air pollution from the combustion of hydrocarbon fuels can be reduced by the use a ........................................ converter which speeds up the conversion of harmful gases into ......................................... gases. Increasing the amount of air and reducing the amount of ……………………………………. Burned in a car engine can reduce the amount of carbon monoxide and unburned ……………………………….. in the car exhaust.

10. Balance the equation below which shows the burning of methane gas CH4 + O2 CO2 + H2O

Topic 6 Structure and Reactions of Hydrocarbons1. The three homologous series (families) of hydrocarbons are called the ......................................., ....................................... and the cycloalkanes. Alkanes and cycloalkanes are called ....................................... hydrocarbons as their molecules contain only single covalent bonds. Alkanes and cycloalkanes have names that end in -………………………Alkenes are called ....................................... hydrocarbons as their molecules contain a carbon to carbon ....................................... covalent bond. Alkenes have names that end in -……………………..The general formula for the ....................................... is CnH2n+2.Both the alkenes and cycloalkanes have a general formula of ....................................... .

2. Isomers have the same ....................................... formula but different ....................................... formulae.

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3. Cracking liquid paraffin. Label the diagram using the words below

heat aluminium oxide catalyst liquid paraffin bromine solution

4.

Give the letters for the correct answers. In some questions there is more than one correct answer.Identify:

(a) an alkane. ……………………(b) an alkene ……………………(c) a cycloalkane ……………………(d) an unsaturated hydrocarbon ……………………(e) a hydrocarbon with the formula C3H6. ……………………(f) two hydrocarbons with the same molecular formula ……………………(g) the hydrocarbon which is an isomer of E ……………………(h) a hydrocarbon which quickly decolourises bromine solution ……………………(i) two hydrocarbons which are isomers ……………………(j) methane ……………………(k) ethane ……………………(l) ethene ……………………

5. a) Name the alkane with i) three carbon atoms …………………………………………………. ii) four carbon atoms …………………………………………………. b) Name the alkene with i) two carbon atoms …………………………………………………. ii) six carbon atoms ………………………………………………….

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Topic 7 Properties of Substances

1. An electric current in a ……………….…… is a flow of electrons. All metals and the non-metal element …………………………………………………. conduct electricity. In a d.c. supply the electrons flow from the …………………………………………………. electrode to the …………………………………………………. electrode. Metal compounds do not conduct in the …………………………………………………. state but they will conduct when ……………………………………………… or when they are ……………………………………………… in water. Passage of electricity through an ionic solution causes the ionic compound to break down – this is called ……………………………………………… . Compounds formed between a metal and a non-metal have …………………………………………… bonding. Solid ionic compounds do not conduct as the …………… are not free to …………………… .

2. Metal atoms can form ………………………………………… charged ions by the metal atom ……………………………… electrons. Non-metal atoms can form ……………………………………… charged ions by the non-metal atom …………………………………… electrons. Compounds which contain only non-metal atoms are usually made up of covalent ………………………………………………. Compounds which are made up of a metal bonded to non-metal(s) are usually ionic. Ionic solids exist as large ……………………………………………… containing millions of charged ions. As the ionic network contains many millions of strong ionic bonds the melting point of these compounds is …………………………

Most covalent compounds exist as ………………………………………………. Inside the molecule the atoms are bonded by a strong ……………………………………………… bond. Between the molecules there are only weak …………………… ……………….. ……………………………. forces. This means that these compounds have ……………….. melting and boiling points.

A few covalent substances like diamond (a form of the element ……………………………………) and silicon dioxide (sand) are made up of a covalent ……………………………………………… These substances have only strong ……………………………………………… bonds and so have very ……………………………… melting points.

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3. Most ionic compounds …………………………………. in water. Most covalent compounds are ……………………………………………… in water.

4. During electrolysis, electricity is used to break apart an ……………………………………………… compound which is molten or in solution. The positively charged ions are attracted to the ……………………………………………… charged electrode where they gain …………………………………….. . The negatively charged ions are attracted to the ……………………………………………… charged electrode where they ………………………… electrons.

5. Draw and label the apparatus you would use to show that sodium chloride solution conducts electricity.

6. Draw and label the apparatus you would use to electrolyse molten lead bromide. Label the chemicals formed at the positive and negative electrodes.

7. In ionic compounds the metal atoms lose electrons to form positively charged metal ions.9

2+

2-

The non-metal atoms gain electrons to form negatively charged ions. Complete the table below which shows a number of atoms and ions.

Atom or ion Symbol No. of No. of No. of Electronprotons electrons neutrons arrangement

sodium atom

sodium ion

chorine atom

chloride ion

Magnesium atom

Magnesium ion

Oxygen atom

Oxide ion

8. Name the electrodes and missing labels in this experiment where copper(II) dichromate is being electrolysed.

.................................. electrode

blue colour due to ................... ions orange colour due to ................................... ions

copper(II) dichromate gel

9. Write the formulae for:(a) sodium chloride (b) calcium bromide (c) copper(II) hydroxide

(d) iron(III) nitrate (e) ammonium sulphate (f) iron(II) sulphide

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.................................. electrode

2+

2-

10. Write ionic formulae for (a) aluminium sulphate (b) calcium nitrate

(c) ammonium carbonate (d) nickel(II) sulphate

Topic 8 Acids and Alkalis1. The formula for hydrochloric acid is ....................... The formula for nitric acid is ....................................... The formula for sulphuric acid is ......................................

2. The pH of pure water and other neutral solutions is ......................... The pH scale measures how acidic or ........................................ a solution is. The pH scale goes from 0 to ............ Solutions with a pH value of .................. than 7 are acidic. Solutions with a pH value of ...................... than 7 are alkaline. Soluble metal oxides form ........................................... solutions when they dissolve in water. Soluble non-metal oxides form ................................. solutions when they dissolve in water. e.g. Substance pH when dissolved in water

calcium oxide greater than 7 (alkali)sulphur dioxidelithium oxidecarbon dioxidenitrogen dioxidesodium oxide

3. All acid solutions contain more ................................... (H+) ions than ........................................... (OH-) ions. Acid solutions form ................................. gas at the negative electrode when they are electrolysed – this shows that acid solutions contain the ............................................... ion. Hydrogen gas burns with a ............................... – this is the test for hydrogen.

4. Metal oxides and metal hydroxides that dissolve in water form ........................................ solution. It is the metals in groups 1 and 2 of the Periodic Table that form soluble oxides. So sodium oxide, ................................ oxide, lithium hydroxide, ..................................... hydroxide form alkali

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solutions when dissolved in water. Alkali solutions contain more ...................................... (OH-) ions than ...................................... (H-) ions.

Topic 9 Reactions of Acids1. A neutralisation reaction occurs when an .............................solution and an ........................................ solution cancel each other out. When an acid solution reacts with an alkali solution a ............................ and water are formed.

2. Complete the table below which shows some everyday substances that can be used as neutralisers.

Substance What it is used to neutraliseMilk of magnesia Acid indigestionBaking SodaVinegarLime

3. Underline the substances below which will neutralise an acid solution.

copper, copper sulphate, magnesium oxide, silicon, sodium nitrate,

sodium carbonate, zinc, bromine solution, lithium hydroxide, water

4. Metal oxides, metal hydroxides, metal carbonates and MAZIT metals are all substances which will neutralise .................................... . We call substances which neutralise ................................. bases.

5. The MAZIT metals are magnesium, ........................................, ........................................, ........................................, and ......................................... When a MAZIT metal reacts with an acid solution the gas ........................................ is given off and a salt is formed.6. When a carbonate (or hydrogen-carbonate) reacts with an acid the gas .................................. .................................. is given off and a salt and water are formed. Carbon dioxide gas turns ............................. ...................................... chalky. This is the test for carbon dioxide.

7. Hydrochloric acid (HCl(aq)) forms salts called ........................................ . Sulphuric acid (H2SO4(aq)) forms salts called ........................................ . Nitric acid (HNO3)forms salts called .........................................

8. Complete the following word equations:-

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(a) Sodium hydroxide + nitric acid ........................................ ........................................ +........................................ (b) Potassium carbonate + sulphuric acid potassium sulphate + ........................... .......................... + water (c) Magnesium + ........................................ acid magnesium chloride + ........................................

9. The following is an example of a neutralisation reaction.NaOH + HCl NaCl + H2O

If 30 ml of sodium hydroxide is neutralised using 40ml of 0.25 mol/l hydrochloric acid, calculate the concentration of the sodium hydroxide solution. Method of calculation:-

C x V x P(acid) = C x V x P (alkali) [P(acid) = No. of H+ ions from acid P(alkali) = No. of OH- ions from alkali)

10. What volume of 0.1 mol/l sulphuric acid (H2SO4) is required to neutralise 40ml of 0.2 mol/l potassium hydroxide (KOH)?

11. A table of solubilities is found in the data booklet on page ....................... A precipitation reaction occurs when an insoluble ................................... is formed when two solutions are mixed.

Name the precipitate formed in each of the following reactions. (a) copper sulphate + sodium carbonate ................................................................

(b) lead nitrate + sodium iodide ..................................................................

12. Describe how solid copper sulphate can be formed from copper carbonate and sulphuric acid.

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13. Use the relationship shown below

mass

n gfm to calculate

(a) The number of moles of sodium hydroxide (NaOH) in 200g of sodium hydroxide.

(b) The mass of sodium carbonate (Na2CO3) present in 0.05 moles of sodium carbonate.

14. Use the relationship shown below

n

C V (litres)

to calculate (a) The number of moles of potassium hydroxide present in 200 cm3 of 0.5 mol/l potassium hydroxide solution.

(b) What is the concentration of a hydrochloric acid solution that contains 0.1 moles of hydrochloric acid in 200ml of solution?

15. Using both of the relationships in 13 and 14 , calculate the mass of zinc chloride, ZnCl2, present in 250cm3 of 0.1 mol/l zinc chloride solution.

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Topic 10. Making Electricity1. Electricity is a flow of charged particles. The particles flowing through metal wires are .............................. The charged particles flowing through an ionic solution are ........................... Electricity is produced by a ..................................... reaction in a cell. When the chemicals in the cell are ................................. ...................... the cell may have to be replaced by a new one. Some types of cells such as lead/acid and nickel/cadmium can be ..................................................

2. An electrochemical cell is formed when two ...................................... metals are placed in a conducting solution called an ................................................. The bigger the gap between two metals in the electrochemical series (page 7 of data booklet) the ....................................... the voltage of the cell. Electrons always flow from the metal ................................... in the electrochemical series to the one ...................................... in the series.

3. Use these words to label the diagram of a zinc/copper cell.

ion bridge solution of Cu2+(aq) ions zinc electrode

electron flow solution of Zn2+(aq) ions copper electrode

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The ion bridge complete the circuit by allowing a flow of ............................ between the two beakers.

4. When a chemical loses electrons the reaction is called ........................................................... When a chemical gains electrons the reaction is called .......................................................... In the cell shown above the ion electron equations can be written for the oxidation and reduction reactions by using the electrochemical series on page 7 of the data booklet.

Of the two metals copper is ..................................... down in the electrochemical series. This reaction stays as written ie as

Cu2+aq) + ....................... ......................... This is the ............................................... reaction The zinc is ............................ up in the electrochemical series. The ion-electron equation on page 7 is reversed ie Zn(s) .............. + ................. This is the ............................................... reaction.

5. When a metal ...................... in the electrochemical series is added to a solution containing ions of a metal lower down in the electrochemical series a .................................................... reaction occurs. e.g. Zn(s) + Cu2+SO42-(aq) ...................(s) + ................................(aq) The sulphate ions are not changed in any way in this reaction – they are called the .......................................... ions. In this reaction the zinc is oxidised and the copper(II) ions are .............................................. As the reaction has both reduction and oxidation taking place it is called a ................................. reaction.

Topic 11 Metals

1. Metals conduct electricity when ............................ or molten. Other properties of metals include good conductivity of ................................., strength, easily shaped (..........................................) and ductility. The supply of metals is ...................................... and so they are recycled to make supplies last longer.

2. Metals react with oxygen to form metal ........................................... The more reactive the metal, the more energy is ................................. ....................... in the reaction. Very reactive metals such as the ..................................... metals in group ......... are stored under oil to stop them reacting with oxygen in air.

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3. Some very reactive metals react with water. These are the .............................. metals in group ........ of the periodic table. When an alkali metal reacts with water the products of the reaction are .................................................. gas and an ..................................... solution of the metal hydroxide.

3. The MAZIT metals are the metals Magnesium, ..........................................., .............................., ......................... and ......................... . The MAZIT metals react with acid solutions to form a .................................. and ........................................ gas. Metals lower than hydrogen in the electrochemical series such as ........................ and ........................... do not react with acid solutions.

4. A rock which contains sufficient metal to make it worthwhile extracting the metal is called an ............. Some very unreactive metals such as ..................................... and .................................... can be found as the pure metal in the Earth’s crust. Unreactive metals such as mercury can be obtained from their ores by ........................ alone.

5. The metals from zinc to copper in the electrochemical series can be extracted from their ores by mixing the ore with ........................................... and then strongly heating the mixture.

6. The most reactive metals are obtained from their ores using electricity.

7. Iron is produced from iron ore in a .................................. furnace. The key reactions which take place are:-

C + O2 -> ......................... production of carbon dioxideC + CO2 -> 2....................... production of carbon monoxideFe2O3 + 3CO -> 2............ + 3 .............. production of iron and carbon dioxide

8. An .................................... is a mixture of metals.

9. To calculate the percentage composition of iron in iron(III) oxide1) Write the formula ie Fe2O3

2) Calculate the formula mass (2 x 56) + (3 x 16) = 160

3) Calculate the percentage of iron x 100 = 70%

(a) Calculate the percentage of nitrogen in sodium nitrate (NaNO3).

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(b) Calculate the percentage of copper in copper(II) oxide.

10. To calculate the empirical (simplest) formula of compound that contains 3 g of carbon and 1 g of hydrogen.

Divide the mass of each element by its relative atomic massC H 3 112 1

= 0.25 1 Divide by the smallest number

0.25 10.25 0.25

= 1 4Whole number ratio gives the empirical formula = CH4

(a) A lead compound on analysis was found to contain 0.63g of lead and 1.41 g of iodine. Calculate the empirical formula for this compound.

(b) A compound contains 2.0g of calcium, 0.6g of carbon and 2.42g of oxygen. Calculate the empirical formula of this compound.

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Topic 12 Corrosion.1. Corrosion is a .............................. reaction that occurs on the ................................. of a metal changing it from an element into a compound. Different metals corrode at ............................................ rates. Corrosion of iron is also known as ........................................... . Both ................................ and .................................... (from air) are needed for rusting. Rusting occurs much faster if there is an electrolyte such as ..................... solution present.

2. When iron rusts the iron atoms ...................... two electrons to form Fe2+(aq) ions. This is an example of an oxidation reaction. The electrons that are lost by the iron atoms are gained by the ......................................... and ................................. molecules to form hydroxide ions. Complete these ion electrons equations for these reactions (use page 7 of the data booklet to help you) Fe(s) ............... + ............... 2H2O(l) + O2 (g) + 4e- ...............

3. Ferroxyl indicator can be used to show the extent of the rusting process. Ferroxyl indicator turns ................. in the presence of iron(II) ions. Ferroxyl indicator turns ....................... in the presence of hydroxide ions.

4. Salt spread on roads to keep them free of winter ice dissolves in water to form an ........................................ solution which speeds up the rate of corrosion of car bodies.

5. A surface barrier which stops .................... and ............................ getting to the surface will prevent iron rusting.

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Paint, ..........................., ............................. and ................................. can all be used to cover the iron with a protective outer coating. In electroplating, ................................................. is used to cover the surface of iron with a layer of another metal e.g. in nickel plating the iron is covered with a protective layer of .................................................. Galvanising involves covering iron with a protective layer of ............................................... In tin-plating, ................................. containers are given a thin layer of tin to protect the iron underneath from rusting.

6. Iron will not rust if electrons are ......................................... onto the iron. In sacrificial protection iron is connected to a more reactive metal such as ...................................... or .................. During sacrificial protection, ......................................... flow from the metal higher in the electrochemical series onto the iron, stopping the iron rusting. By connecting iron to the ............................................ terminal of a battery, electrons will be pushed onto the iron, stopping it rusting.Topic 13 Plastics and Synthetic Fibres.1. Plastics and synthetic fibres are polymers. Polymers are made by from chemicals obtained from ..................... ...................... . Some polymers like cotton and wool are ................................. while others such as ............................................. and .......................................... are man-made.

2. The uses of polymers are related to their properties. Poly(ethene) is used to make carrier bags as it is ................................................. and ..................................... Poly(styrene) is used for packaging as it is .................................................. P.V.C. is used to cover electrical cables as it is an .............................................................

3. Plastics can cause environmental damage. they are non ......................................................... This means that they are not broken down by

bacteria and weather. when they burn polymers produce ......................................... gases. e.g polyurethane

forms ............................................ ............................................., PVC produces carbon monoxide and ................................ ........................................

4. Some plastics soften on heating and can be reshaped. These plastics are said to be .......................................... Some plastics do not soften on heating – they are called ............................................. polymers.

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5. Addition polymers are made from small .................................................. monomer molecules. The unsaturated monomer molecules are produced by ............................................... long chain hydrocarbon molecules. When many small monomer molecules join together they form a long chain molecule called a ................................. Addition polymerisation occurs when many unsaturated monomers join to form a ...........................................

Monomer PolymerEthene Poly(ethene)Propene

Poly(vinylchloride)

6. In the formation of an addition polymer, the carbon to carbon ................................. bond in the monomer molecule breaks and becomes a ................................... bond in the polymer.

This is propene CH3 HC = CH H

Show how three propene monomer molecules link together to make poly(propene).

Draw the repeating unit in poly(propene).

Topic 14 Fertilisers.

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1. The increasing world ....................................... has led to the need for more efficient .......................... production. Growing plants require three essential elements to ensure healthy plant growth. The three essential elements are ............................................. , .................................................... and ............................................. . Peas, ................................... and ............................. plants (called the legumes) have nitrifying ................................... in root nodules. These nitrifying ........................................... can use the ........................................ gas in the air and turn it into soluble nitrogen compounds such as ...................................... . This is called nitrogen .............................. 2. Fertilisers must be water ............................. so that the plants can absorb the fertiliser through its roots. If there is very heavy rainfall soon after a fertiliser is added to a field, much of the fertiliser can be washed out of the soil and into nearby .................................. This can lead to rivers being covered in ....................

3. In the Haber Process , ....................................... (from the air) and ..................................... (from water or methane) are combined to make ............................................... (NH3). The Haber process uses an ..................... catalyst, a temperature of about ..................oC and a pressure of about ......................... times atmospheric pressure. The reaction is reversible and high ................................. is used to improve the yield of ammonia. Any unreacted nitrogen and hydrogen are ................................................. .

4. Ammonia is an ............................................ gas (it turns pH paper ....................) with a ................................. small. Ammonia is very .................................... in water. When it dissolves in water ammonia forms a solution of ............................................. ................................................... (NH4OH).

5. Ammonia can be made in the laboratory by reacting any ammonium salt (such as ........................................... ........................................) with a base (such as ................................ ...................................).

6. Complete the following word equations.

(a) ammonium hydroxide + nitric acid ......................................... .................................... + water

(b) ammonium hydroxide + .................................................. acid ammonium sulphate + water

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(c) ......................................... ........................................... + hydrochloric acid ammonium chloride + water

7. In a lightning storm, ..........................................gas and oxygen gas in the atmosphere can combine to form nitrogen dioxide. When nitrogen dioxide gas dissolves in water it forms ................................ acid. Nitrogen is very unreactive and it needs a great deal of ............................................ energy to make oxygen and nitrogen react.

8. In the Ostwald Process, ammonia gas is oxidised by passing ammonia and air over a heated ............................... catalyst. The product of this reaction are nitrogen oxides which react with water to form ............................ acid. The reaction is very exothermic and once started it does not have to be .................................... to keep the temperature at 800oC

9. Calculations using a balanced equation. What mass of carbon dioxide is formed when 4kg of methane is burned? CH4 + 2O2 CO2 + 2H2O 1 mole 1 mole (1 x 12) + (4 x1) (1 x 12) + (2 x 16) 16 g 44 gSo 16 kg 44 kg

So 4 kg 44 x

= 11 kg

Examples for practice.(a) Calculate the mass of oxygen that can be formed when 68g of hydrogen peroxide (H2O2) decomposes.

2H2O2 2H2O + O2

(b) Calculate the mass of iron that can be formed from 480 kg of iron(III) oxide.

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4

16

Fe2O3 + 3 CO 2Fe + 3CO2

10. Percentage Composition. Calculate the percentage of nitrogen in ammonium nitrate.

formula of ammonium nitrate = NH4NO3

gram formula mass of NH4NO3 = (2 x N) + (4 x H) + (3 x O) = (2 x 14) + ( 4 x 1) + (3 x 16)

= 28 + 4 + 48 = 80

% of nitrogen = x 100

= 35%Examples for practice.(a) Calculate the percentage of nitrogen in sodium nitrate (NaNO3)

(b) Calculate the percentage of potassium in potassium sulphate (K2SO4)

(c) Calculate the percentage of nitrogen in calcium nitrate - Ca(NO3) 2

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Topic 16 Carbohydrates1. Photosynthesis is the process by which ........................................... make carbohydrates from ............................. ............................................. and ......................................... The process uses ........................... energy from the Sun. The catalyst for the reaction is the green pigment called .............................................. . During photosynthesis the plants release the gas ............................................ into the atmosphere. Balance the photosynthesis reaction shown below ................CO2 + ..................H2O C6H12O6 + ..........O2

carbon dioxide water glucose oxygen

2. Respiration is the process by which animals and plants obtain ............................. by breaking down carbohydrates. The carbohydrate burns in oxygen giving out energy and the waste products ...................................... ............................... and ................................. The respiration reaction is the exact ....................................... of the photosynthesis reaction.

3. Between them the photosynthesis and respiration reactions maintain the balance of the gases .................................... ............................... and ..................................... in the atmosphere.

4. Carbohydrates contain the elements ......................................., ......................................................... and .......................... The table below shows some examples of carbohydrates.

Monosaccharides ..................................................... Polysacchardies

Formula C6H12O6 C12H22O11

............................................Examples ............................... sucrose starch

fructose ................................... cellulose

5. Iodine solution is used as the test for ........................................ . When added to ........................................ iodine solution changes colour from red/brown to ..........................................................

6. Benedict’s solution is used as the test for Reducing sugars. When heated with Benedict’s solution glucose, fructose and maltose change the colour of the Benedict’s solution from blue to ..................................- ..................... Sucrose is a non-reducing sugar and so it does not react with ............................................... solution.

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7. In a plant glucose monomer molecules are joined together with a loss of water to form the polysaccharide ........................................... . This type of polymerisation is called .................................................... polymerisation.

8. During ......................................... large starch molecules break down by reacting with .................................. to form glucose. This is an example of a ....................................... as it involves the breakdown of a molecule by reacting it with water. The small glucose molecules can pass through the walls of the ........................ intestine into the bloodstream. In the body it is the enzyme, ......................................, found it saliva and ......................................................... acid in the stomach that brings about the hydrolysis of starch into glucose.

9. Glucose and fructose are ...................................... as they have the same molecular formula (C6H12O6) but different structures. Sucrose and maltose are ...................................... as they have the same molecular formula (C12H22O11) but different structures.

10. Carbohydrates in fruits and vegetables can be turned into alcohol by a process called ..................................... The carbohydrate in grapes is used to make ......................... . Whisky is made from carbohydrate in grain. Cider uses carbohydrate in ................................... The breakdown of glucose to alcohol (ethanol) by fermentation is catalysed by the enzyme, .............................., present in yeast.

11. Enzymes can be affected by changes in ................. and .......................................................... High concentrations of alcohol also stop enzyme working and so fermentation can only produce alcoholic drinks with about 12% alcohol. To obtain alcoholic drinks (spirits) with an higher alcohol concentration (40%) the alcohol and water are separated by ............................................. ....................................... The alcohol and water are able to be separated in this way as they have different ....................................... points.

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Note:- These are some, but certainly not all, of the important facts that you need to know from Standard Grade Chemistry. Your Revision should use many sources of information – your worksheets, summary sheets, formula and calculations booklet and past papers are other sources of information and examples for practice.

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