Name ................................................ Homework 3.1Date due ..........................................

1. Name a) two acidic oxides.

…………………………………………………………………………………………………………………1

b) two basic oxides.

…………………………………………………………………………………………………………………1

2. Complete the following:- In general metal oxides are ………………………………… and non-metal oxides are ………………………. When non-metal oxides dissolve in water they turn pH paper …………………………… but soluble metal oxides turn pH paper ……………………………… .

2

3. What does the pH scale measure? ………………………………………………………………………………………….. 1

4. Explain why acid and alkali solutions are much better conductors than pure water. ……………………………………………………………………………………………………………………………………………………… 1

5. a) Write an equation showing the dissociation of water molecules into ions. ……………………………………………………………………………………………………………………………………………………… 1

b) Explain why water is a neutral solution. …………………………………………………………………………….. ……………………………………………………………………………………………………………………………………………………… 1

6. Consider the grid below.

A more H+(aq) ions than 100 cm3 of pure water.B the same number of H+ (aq) ions as 100 cm3 of pure water.C more OH–(aq) ions than 100 cm3 of pure water.D the same number of OH––(aq) ions as 100 cm3 of pure water.E equal numbers of H+ (aq) ions and OH– (aq) ions.F more OH– (aq) ions than H+ (aq) ions.G more H+ (aq) ions than OH– (aq) ions.

Which the two boxes shows a true statement about 100 cm3 ofa) calcium hydroxide solution (lime water) ………………………………and……………………………… 1b) dilute sulphuric acid. ………………………………and…………………………….. 1

9. Consider the grid below

A H2O(l)B H+(aq) C H2 (g) D OH–(aq) E O2 (g)

a) Identify the two entities that are present in equal concentrations in a neutral solution. ………………………………………………………………………………………………………………………………………………….. 1b) Identify the entity whose concentration is reduced when water is added to an alkali solution. ………………………………………………………………………………………………………………………………………………….. 1

10.A B C carbon dioxide sodium oxide aluminium oxideD E F calcium hydroxide sulphur dioxide hydrogen oxide

a) Which two boxes show oxides which are acidic? .................. and .................... 1 b) Which two boxes show a substance that dissolves in water to give a solution with a pH of more than 7? .................. and .................... 1

11. Different acids can be classified as strong or weak acids. Acids have many different uses. Ethanoic acid is a weak acid which is used as vinegar in foods. Sulphuric acid, which is used in car batteries, is a strong acid. The weak acid which is used in some wound

dressings is called boric acid. Rust removers contain the strong acid, hydrochloric acid.

Present all of this information as a table with three suitable headings.

2Name ................................................ Homework 3.2Date due ..........................................

1. A Rate of forward reaction.B Concentration of reactants.C Concentration of products.D Rate of back reaction.

For a reversible reaction at equilibrium, which two boxes show factors that area) equal?

……………………………………………………………………………………………………………………. 1b) constant, but not equal? ……………………………………………………………………………………… 1

2. Hydrochloric acid is a strong acid whereas ethanoic acid is a weak acid. Explain the difference between a strong acid and a weak acid. ………………………………………………………………………………………………………………………………………………….. ………………………………………………………………………………………………………………………………………………….. ………………………………………………………………………………………………………………………………………………….. ………………………………………………………………………………………………………………………………………………….. 2

3. An experiment comparing the characteristics of 0.1 mol l-1 solutions of

Total marks = 16

hydrochloric acid and ethanoic acid was carried out. Supply the missing information which would correctly complete the table.

Characteristic 0.1 mol l-1 HCl 0.1 mol l-1 CH3COOH

pH 1 ……………………………………………

current flowing when equal volumes tested 60 mA

………………………………………….in same conductivity cell

rate of reaction with0.1 g samples of very fast …………………………………………….

3powdered chalk

4. Underline the substances listed below which would neutralise vinegar (a solution of ethanoic acid).

lime (calcium oxide): lemon juice: sodium hydroxide:

sodium carbonate: sodium chloride: nitric acid:lemonade. magnesium oxide: water. 2

5. Describe how a farmer could test the pH of the soil on his farm. How would the farmer treat the soil if it had a pH = 4?

………………………………………………………………………………………………………………………………………………….. ………………………………………………………………………………………………………………………………………………….. ………………………………………………………………………………………………………………………………………………….. 2

6. A pupil was given 2 zinc ores. One was a zinc oxide compound and the other a zinc carbonate compound. Describe a chemical test which would allow the pupil the determine which ore was which. …………………………………………………………………………………………………………………………………………………..

………………………………………………………………………………………………………………………………………………….. ………………………………………………………………………………………………………………………………………………….. 2

7. Some rain water fizzed vigorously when added to sodium carbonate was added to it.a) Which gas is given off in this reaction? ……………………………………………………………………….. 1b) How would you test the gas to prove its identity? ………………………………………………………… ………………………………………………………………………………………………………………………………………………….. 2 c) What does this suggest about the rain water? ……………………………………………………………. 1

d) Draw a labelled diagram of the apparatus you would use to carry out this reaction and collect the gas.

2

Name ................................................ Homework 3.3Date due ..........................................

1. Complete the following sentences. Ammonia is a ………………………………………………. gas with a characteristic smell. Ammonia is ………………………………… dense than air and is very ……………………………………in water forming an ……………………………………………………… solution. The fact that ammonia turns moist pH paper ………………………………… is used as the test for ammonia..

3 2. Complete the table below giving the formula of the acid and the name of the

Total marks = 19

salt it forms. The first example has been done for you

Acid. Formula of Acid Name of Salt

Phosphoric acid H3PO4 phosphate

Hydrochloric acid ……………………………………………………………………………………………. H2SO4…………………………..

Nitric acid ………………………….. nitrate3

3. A sample of nitric acid was neutralised using sodium hydroxide solution forming sodium nitrate and water.a) Write the reaction as word equation. …………………………………………………………………………………………………………………………………………………………….1

b) Write the reaction as a balanced chemical equation. …………………………………………………………………………………………………………………………………………………………….1

4. The ionic equation below shows the reaction between sodium hydroxide and sulphuric acid solutions.

2Na+OH–(aq) + (H+)2SO42-(aq) (Na+)2SO42-(aq) + 2H2O(l)

a) Write the formulae for the spectator ions in this reaction. ………………………………………… 1

b) Rewrite the ionic equation missing out the spectator ions.

…………………………………………………………………………………………………………………………………………………………….1

5. When a solution of a metal nitrate was added to potassium chloride solution a white solid was formed.a) What name is given to this type of reaction in which an insoluble solid is formed when two solutions are mixed? ……………………………………………………………………………………………………………………………………………………… 1

b) Using the table of solubilities on page 5 of the data book identify a metal nitrate that

could have been given this result. ……………………………………………………………………………………………………………………………………………………… 1

6. A B Coxygen hydrogen nitrogen

D E Fchlorine sulphur dioxide carbon dioxide

a) Use the grid to identify the gas produced when hydrochloric acid reacts with magnesium carbonate.

……………………………………………………………………. 1

b) Identify the gas produced when zinc reacts with sulphuric acid.

……………………………………………………………………. 1

7. Describe, in detail, how you would prepare a pure, dry sample of copper sulphate in the laboratory staring with copper carbonate and sulphuric acid. You have available all the usual laboratory apparatus.

…………………………………………………………………………………………………………………………………………………….

…………………………………………………………………………………………………………………………………………………….

…………………………………………………………………………………………………………………………………………………….

…………………………………………………………………………………………………………………………………………………….

…………………………………………………………………………………………………………………………………………………….

…………………………………………………………………………………………………………………………………………………….

…………………………………………………………………………………………………………………………………………………….

……………………………………………………………………………………………………………………………………………………. 3

Name ................................................ Homework 3.4Date due ..........................................

1. Calculate the number of moles of solute present in each of the following:-a) 250 cm3 of 3 mol l-1 ammonia solution

2

b) b) 100 cm3 of 0.1 mol l-1 potassium nitrate

2

2 A pupil titrated citric acid solution against sodium hydroxide solution. She found that 15 cm3 of 0.1 mol l-1 citric acid were needed to neutralise 45 cm3 of 0.1 mol l-1 sodium hydroxide.

a) Calculate the number of moles of citric acid reacted?

2

b) Calculate the number of moles of sodium hydroxide reacted?

2c) How many moles of sodium hydroxide react with 1 mole of citric acid?

……………………………………………………………… 1

Total marks = 17

3. Sodium hydroxide reacts with nitric acid as follows

In a titration, 30 cm3 of nitric acid neutralised 20 cm3 of 0.2 mol l-1 sodium hydroxide solution. Calculate the concentration of the nitric acid.

2

4. Over the last 50 years, a Scottish estate has been keeping a log of the number of trout caught in a highland loch. The log also records the average pH of the loch water. A table from the log is shown below.

Years 1950 1960 1970 1980 1990 - 1959 - 1969 - 1979 - 1989 1999

number of 800 560 200 70 20Trout caught

average pH of 6.4 5.6 4.5 3.6 3.1Loch water

a) What conclusion can be drawn about the effect of pH on the number of trout caught? ……………………………………………………………………………………………………………………………………………………….. 1b) Draw a bar chart showing the number of trout caught in each year group.

2

Name ................................................ Homework 3.5Date due ..........................................

NaOH(aq) + HNO3(aq) NaNO3(aq) + H2O

NaOH(aq) + HNO3(aq) NaNO3(aq) + H2O

Total marks = 14

1.. A pupil placed a strip of nickel on top of a piece of silver and connected both to a voltmeter, but the meter gave no reading.

a) Explain why there was no reading on the voltmeter. ……………………………………………………. ……………………………………………………………………………………………………………………………………………………… 1

b) What would the pupil have to do to get a reading on the voltmeter? ……………………… ……………………………………………………………………………………………………………………………………………………… 1

c) The pupil looked up nickel in the electrochemical series and found that it was between zinc and iron. Which pair of the following metals would give the highest meter reading? i) Nickel and silver or zinc and silver?

…………………………………………………………………………… 1 ii) Nickel and silver or iron and silver?

…………………………………………………………………………… 1

d) What is meant by the term ‘electrolyte’? ………………………………………………………………………. ……………………………………………………………………………………………………………………………………………………. 1

2. The results obtained when the metals A,B and C were tested in a cell using metal D as a standard are shown below.

a) Suggest the name of a suitable electrolyte solution ……………………………………..………………….. 1b) Metals Voltmeter reading / V

A and D 0.75B and D 1.65C and D 1.18

i) Place the four metals in an electrochemical series starting with the metal highest

Filter paper soaked in an electrolyte solution

metal D

metal A voltmeter

in the series. ……………………………………………………………………………………………….. 1

3.

Three metals were tested in the above experiment. The results are shown below. Metal tested Voltage / V Direction of electron flow

R 0.3 zinc to metal RS 0.4 metal S to zincT 1.0 zinc to metal T

a) State which one of the four metals (R,S,T and Zinc) is the highest in the electrochemical series. …………………………..…..

1b) Arrange the four metals in order in the electrochemical series, with the highest first.

…………………. ……………….. ………………… ……………………

1

4.

a) On the above diagram show the direction of electron flow in the external circuit? 1b) What difference there would be in the voltage reading if the zinc and zinc sulphate solution were replaced by magnesium and magnesium sulphate solution. ………………………………………………………………………………………………………………………………………….….. 1c) Write an ion electron equation for the reaction at i) the zinc electrode………………………………………………………………………………………………………… 1

Filter paper soaked in an electrolyte solution

zinc

metal tested voltmeter

Sodiumnitratesolution

magnesium leadcoppersulphatesolution

zincmagnesiumsulphatesolution

A B C Daluminium

zincsulphatesolution

ii) the copper electrode.……………………………………………………………………………………………….1

d) Which electrodei) increases in mass?

……………………………………………………………………………………………………………1

ii) decreases in mass?………………………………………………………………………………………………………….

1

Name ................................................ Homework 3.6Date due ..........................................

1. Each box in the grid below shows a test tube containing a solution and a piece of metal.

a) Which two boxes show a test tube where a reaction occurs? …………… and ………………. 2

b) What name is given to this type of reaction? …………………………………………………………………… 1

2 State what is meant by each of the following terms.a) oxidation.

……………………………………………………………………………………………………………………………………….. 1b) reduction. …………………………………………………………………………………………………………………………………... 1c) redox reaction.

Total marks = 15

…………………………………………………………………………………………………………………

……….. 1

3. In which of the following state whether or not a displacement reaction will occur.a) magnesium and zinc sulphate solution. ……………………….b) copper and lead nitrate solution. ……………………….c) iron and tin chloride solution. ……………………….d) iron and sodium chloride solution. ……………………….

2

4. When zinc reacts with silver(I) nitrate solution the reactants are zinc atoms and silver(I) ions.a) Balance the equation for this reaction.

Zn2+(aq) + Ag(s) b) Which reactant is oxidised?

……………………………………………………………………………………………… 1c) Write an ion-electron equation for the oxidation. ………………………………………………………………………………………………………………………………………………………….. 1d) Which reactant is reduced?

……………………………………………………………………………………………… 1e) Write an ion-electron equation for the reduction. ………………………………………………………………………………………………………………………………………………………….. 15. Apply the terms oxidation, reduction or redox to each of the following.a) silver changing into silver(I) ions. .…………………………………………………

1

b) Mg(s)

Mg2+(aq) + 2e– ……………………………………………………1

c) 2H+(aq) + 2e–

H2(g)………………………………………………….. 1

d) 2I–(aq)

I2(aq) + 2e– ……………………………………………………1

6. Iron(III) chloride solution reacts with potassium iodide solution in a redox reaction.

Zn(s) + Ag+(aq)

Zn(s) + Ag+(aq)

2FeCl3 + 2KBr 2FeCl2 + Br2 + 2 KCl

2FeCl3 + 2KBr 2FeCl2 + Br2 + 2 KCl The grid shows the ions present during the reaction.

A B C D E

Use the data booklet (page 7) to help you with the following questions. a) Identify the ion which is reduced.

……………………………………………….. 1 b) Identify the two spectator ions in the reaction.……………………. and ……………………. 1

7. A chloride ion is formed when a chlorine atom gains one electron.

A The change represents reduction.B The atomic number increases by one.C The particle becomes negatively charged.D The number of electron energy levels increases by one.

E The change represents oxidation

Identify the two true statements about this change. …………………….. and …………………….. 2

Name ................................................ Homework 3.7Date due ..........................................

1. The table shows the world production for different metals

Metal World production (million tonnes per year)

Aluminium 14.4Copper 11.0Tin 5.0Zinc 6.4

Draw a bar graph to show this information.

Cl --

Cl --

K+

K+

Br --

Br --

Fe2+

Fe2+

Fe3+

Fe3+

Total marks = 20

2

2. Our modern world depends on metals. Some metals, such as gold, are found uncombined. Others such as aluminium have to be extracted from their ores.

a) Explain why gold is found uncombined.………………………………………………………………………………… 1

b) What is meant by the term ‘ore’?…………………………………………………………………………………. 1

c) Name two metals which can be extracted from their ores by heating with carbon. ……………………………………………….. and ……………………………………………….

2d) Name a metal which can be extracted from its ore by heat alone. ……………………………… 1

3. Metals take part in many reactions. Identify the two statements which can be applied to magnesium but not to copper.

A It reacts with dilute acid.B It reacts vigorously with cold water.C It reacts when heated with oxygen.D It reacts with zinc sulphate solution..

E It reacts with silver nitrate solution.

……………………….. and ………………………. 2

4. The flow diagram shows how iron is produced in a blast furnace.

a) Name X and Y in the flow diagram. X ………………………………………………… Y …………………………………………………… 2b) Carbon is added to the blast furnace to raise the temperature as it burns. Explain the other reason why the carbon is added.……………………………………………………………………………………………………………………………………………….………….. 1c) Why is limestone added?……………………………………………………………………………………………………………………………………………..………….. 1d) The waste gases leaving the blast furnace are very hot. Suggest how this heat could be used to reduce the cost of running the blast furnace. …………………………………………………………………………………………………………………………………………………………….. 1

5. Steel for different uses can be made by adding different metals to iron. Titanium is added to make steel suitable for use in rockets. Magnets are made from steel which contains cobalt. The steel for railway lines is made by adding manganese to iron. Drill bits require a very hard steel. This is made by adding tungsten to the iron. Present the above information in a table with suitable headings

2Name ................................................ Homework 3.8Date due ..........................................

1. a) Explain what happens to the atoms of a metal when the metal corrodes.

………………………………………………………………………………………………………………………………….…………….. 1b) Which two substances have to be present before a metal will corrode? ………………………………………… and …………………………………………………..

1c) Is corrosion an example of oxidation or reduction?

………………………………………………………d) Write an ion-electron equation to show the formation of zinc(II) ions when zinc metal corrodes.

Total marks = 16

………………………………………………………………………………………………………………………………………………………… 1

2. A group of pupils set up the experiment shown below. After 30 minutes they added some ferroxyl indicator solution to each tube.

A B

a) i) What would you expect to see in tube A? …………………………………………………………………… 1ii) Which ion causes this change? …………………………………………

1b) i) What difference would you expect to see in tubes A and B? ………………………………. …………………………………………………………………………………………………………………………………………….. 1ii) Give an explanation for your answer. ………………………………………………………………………………… ……………………………………………………………………………………………………………………………………………………… 1

3. When iron corrodes the iron atoms lose electrons to form iron(II) ions.a) Write an ion-electron equation for the formation of the iron(II) ions.

……………………………………………………………………………………………………………………………………………………… 1 b) The electrons lost by the iron atoms are gained by water and oxygen molecules forming hydroxide ions. Write an ion-electron equation for the formation of the reaction.

……………………………………………………………………………………………………………………………………………………… 14. Paint, oil, grease and plastic are said to provide ‘physical protection’ from corrosion

nail nail

tap watersalt water

when used to coat iron and steel. State what is meant by the terms a) Corrosion

………………………………………………………………………………………………………………………………… 1 b) physical protection …………………………………………………………………………………………………………….. 1

5. Motor car manufacturers are making increased use of zinc-coated steel. This is because of the sacrificial protection given to the steel in the event of the zinc coating being broken thus exposing the steel.a) What name is given to the protecting of steel by covering with zinc? ………………………………………………………………………..

1b) How does the zinc protect the steel (iron) even when the layer is broken? ……………………………………………………………………………………………………………………………………………………….. ……………………………………………………………………………………………………………………………………………………….. ……………………………………………………………………………………………………………………………………………………….. 1

6. A pupil set up the following experiments to study the rusting of iron nails under different conditions. Each of the test tubes contained ferroxyl indicator and an iron nail.

A B C D

a) Identify the experiment in which the iron nail would not rust? …………………………………1

Mg Cu Sn Pb

20°C

40°C

20°C

30°C

tap water sea water sea water tap water

b) Which two experiments would provide a fair comparison of the ability of different metals to affect the ate of corrosion of iron?

…………………….. and ………………………..1

c) In which test tube would the nail rust most quickly? ……………………………… 1

Name ................................................ Homework 3.8Date due ..........................................

1. On some buildings the wooden roof is covered with copper sheets instead of slates.a) Why should the copper roof not be held in position with iron nails? …………………………………. ………………………………………………………………………………………………………………………………………………………………. ………………………………………………………………………………………………………………………………………………………………. 2b) Which metal should be used to hold the copper sheet in position be made of?

…………………………………………………………………………………………………………………

………………………………………… 1

2 Tin plated steel is widely used for making the cans in which many types of food and drink are sold. The contents of such a can are well protected while the plating is intact because tin is quite an unreactive metal. However, once the tin coating is broken, the steel (iron) tends to rust very quickly. Explain why a) The tin layer can stop the steel (iron) underneath from corroding. ………………………………….. …………………………………………………………………………………………………………………………………………………………… 1

Total marks = 16

b) The steel rusts quickly when the tin layer is broken. ……………………………………………………………

……………………………………………………………………………………………………………………………………………………………….

…………………………………………………………………………………………………………………

……………………………………………. 2

3. An experiment was carried out to electroplate a steel spoon with nickel. The apparatus is shown below

a) Explain why the object to be electroplated must be connected to the negative terminal of the power supply. …………………………………………………………………………………………………………………………………………………………… …………………………………………………………………………………………………………………………………………………………… 1b) During the electroplating process, nickel(II) ions are converted into nickel atoms at the negative electrode. Write the ion electron equation for this reaction. …………………………………………………………………………………………………………………………………………………………… 1

4 Buried steel pipelines can be protected against corrosion by connecting the pipe to scrap magnesium buried in the ground alongside the pipe.a) Explain why this type of protection is called ‘sacrificial protection’. ……………………………………………………………………………………………………………………………………………………………….

+–

steel spoon

nickel(II) sulphatesolution

………………………………………………………………………………………………………………………………………………………………. 1b) Explain how the magnesium protects the steel from corrosion. ………………………………………………………………………………………………………………………………………………………………. ………………………………………………………………………………………………………………………………………………………………. 1

5. Kenneth was investigating corrosion.

a) Identify the experiment in which the corrosion of the nail was the most rapid. …………………. 1

b) Identify the experiment in which the nail was sacrificially protected? …………………. 1

7. Identify the two correct statements about the rusting of iron.

A Copper gives sacrificial protection to ironB Iron metal is oxidisedC Iron rusts when attached to the negative terminal of a batteryD Ferroxyl indicator turns pink in the presence of iron(II) ions

E Electroplating provides a surface barrier to air and water

……………………… and ……………………. 2

Total marks = 14