All Saints SecondaryStandard Grade Chemistry

Topic 11 Homework – Metals

General Level

1.Gold and silver are both used to make jewellery.

A / They / are alkali metals.
B / They / conduct electricity.
C / They / are more reactive than copper.
D / They / react with dilute hydrochloric acid.
E / They / are found uncombined in the Earth's crust.

Identify the two statements which are true for both gold and silver.

You may wish to use the data booklet to help you.

2 marks (PS)

2.Many different reactions take place in a blast furnace.

Identify the reaction in which a reactant and a product are elements.

A / C+O2 / / CO2
B / CO2 + C / / 2C0
C / CaCO3 / / Ca0 + CO2
D / 2Fe203 + 3C / / 4Fe + 3C02
E / Fe203 + 3C0 / / 2Fe + 3C02

1 mark (PS)

3.The surface of the planet Mercury has a temperature of 510°C.

a space probe sent to study the surface of the planet would need to be made of metals which would not melt at this temperature.

A / B / C
aluminium / copper / iron
D / E / F
nickel / tin / zinc

Identify the two metals which could not be used in this probe.

You may wish to use page 3 of your data booklet to help you.

1 mark (PS)

4. Gold and silver are both used to make jewellery.

Identify the statement(s) which are true for both gold and silver.

A / They / are not transition metals.
B / They / conduct electricity.
C / They / are found uncombined in the Earth's crust.
D / They / react with dilute hydrochloric acid.
E / They / are more reactive than copper.

1 mark (PS)

5. Metals and their compounds take part in many reactions.

A / Fe203 + 3C0 / / 2 Fe + 3CO2
B / 2Mg + Si02 / / 2Mg0 + Si
C / CuC03 / / Cu0 + CO2
D / 2Zn + O2 / / 2Zn0

(a)Identify the reaction which takes place in the blast furnace.

1 mark (PS)

(b) Identify the reaction which produces a non-metal element.

1 mark (KU)

6.Wilma investigated the reaction of the metals R, S and T with water.

(a)Place the metals in order of reactivity (most reactive first).

1 mark (PS)

(b)Identify a variable that Wilma would have kept constant.

1 mark (PS)

(c)Why is it unsafe to use potassium metal in this experiment?

1 mark (PS)

(d)How would Wilma test the gas to show that it was hydrogen?

1 mark (KU)

7.Solders are mixtures of lead (melting point 328 °C) and tin (melting point

232°C).

The graph shows the melting points of solders containing different percentages of tin.

(a)What name is given to mixtures of metals like solders?

1 mark (KU)

(b)Describe the trend in the melting point of solder as the percentage of tin increases from 20% to 50%.

1 mark (PS)

(c)Use the graph to estimate the melting point of solder containing 90% tin.

1 mark (PS)

8.The percentage of oxygen in air can be found by passing air backwards and forwards over heated copper metal.

(a)Name the compound formed when air is passed over heated copper metal.

1 mark (PS)

(b)Why is the air passed backwards and forwards until there is no further change in volume?

1 mark (PS)

(c)What would you expect the final syringe reading to be if 100 cm' of air was used in the experiment?

1 mark (PS)

9. Hot magnesium ribbon reacts vigorously with steam. It glows very brightly and the products are magnesium oxide and hydrogen gas.

(a)Write an equation, using symbols and formulae, for the reaction taking place in the test tube.

There is no need to balance the equation.

1 mark (KU)

(b)The magnesium oxide which is formed will react with dilute hydrochloric acid.

Name the type of chemical reaction which takes place.

1 mark (KU)

(c)Name the product formed when hydrogen burns.

1 mark (KU)

10.The reactivity of metals can be compared by adding them to a mixture of hydrochloric acid and detergent.

Amy set up five test tubes each containing a different metal.

(a)Name the gas produced when a metal reacts with hydrochloric acid.

1 mark (KU)

(b)Suggest a name for metal X.

You may wish to use page 7 of the data booklet.

1 mark (PS)

(c)Name one factor which Amy would have kept the same to ensure a fair comparison.

1 mark (KU)

11.Fiona was investigating the reaction of two different metals with dilute sulphuric acid.


She changed the concentration of the acid and timed how long it took for each metal to produce 10 cm 3 of hydrogen gas.

Concentration of acid/moles per litre / Time Taken to produce 10 cm3 of gas/second
Metal A / Metal B
1 / 62 secs / 87 secs
2 / 27 secs / 41 secs

(a)How would Fiona have shown that the gas collected was hydrogen?

1 mark (KU)

(b)State whether A or B is the more reactive metal.

1 mark (PS)

(c)Identify a variable that Fiona would have kept constant during her experiment.

1 mark (PS)

12. 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 a steel which contains cobalt. The steel for railway lines is made by adding manganese to the 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.

2 marks (PS)

13.Alloys have many uses. Water taps can be made from brass while solder is used to join metal pipes together. Duralumin is used to make the framework for aeroplanes, however cars and ships are made from steel.

(a)Present this information in a table with suitable headings.

2 marks (PS)

(b) Solder is an alloy of tin and lead only.

The melting point of solder depends on the percentages of tin and lead mixed together.

Percentage of tin / Melting point of solder/°C
25 / 270
45 / 225
65 / 180
85 / 205

(i)What percentages of tin and lead are present in the solder with the lowest melting point?

1 mark (PS)

(ii)Solder is used in electronic circuit boards.

Apart from its low melting point, what other property of solder makes it suitable for use in electronic circuit boards?

1 mark (PS)

Credit Level

1.Reactions can be represented using ionic equations.

A / H+(aq) + OH- (aq) / / 4H2O(l)
B / 2H20(l) + O2(g) + 4e- / / 40H-(aq)
C / 2H+(aq) + C032-(aq) / / H20(l ) + CO2(g)
D / SO2(g) + H2O(l) / / 2H+(aq) + S032-(aq)
E / NH4+(s) + OH-(s) / NH3(g) + H2O(l)

(a)Identify the ionic equation representing reduction.

1 mark (KU)

(b)Identify the ionic equation which shows the formation of acid rain.

1 mark (KU)

(c)Identify the two ionic equations which show the neutralisation of an acid.

1 mark (PS)

2.Identify the statement(s) which can be applied to iron but not to copper.

A / It / displaces tin from a solution of tin chloride.
B / It / reacts with cold water.
C / It / can be obtained by heating its oxide with carbon.
D / It / reacts with dilute hydrochloric acid.
E / It / is displaced from a solution of its chloride by zinc.

1 mark (KU)

3.David was studying the reactions of some metals and their compounds.

He carried out experiments involving magnesium, copper, zinc, nickel, silver and an unknown metal X.

Listed below are some of the observations he recorded.

A / X was more readily oxidised than copper.
B / X oxide was more stable to heat than silver oxide.
C / Magnesium displaced X from a solution of X nitrate.
D / X reacted more vigorously than nickel with dilute acid.
E / Compounds of X were more readily reduced than compounds of zinc.

From his observations, David produced the following order of reactivity.

Identify the two observations which can be used to show that X has been wrongly placed.

2 marks (PS)

4.Zinc occurs in the Earth's crust mainly as zinc sulphide, ZnS. The flow

chart shows the main steps in extracting the metal.

(a)Gas X is a possible cause of acid rain pollution. Suggest a name for X.

1 mark (PS)

(b) (i) What name is given to the type of reaction (Y) taking place between

zinc oxide and dilute sulphuric acid?

1 mark (KU)

(ii) Name the other product, Z, of this reaction.

1 mark (KU)

(c)The zinc sulphate solution is electrolysed and zinc metal forms at the negative electrode.

(Write the ion-electron equation for the formation of zinc metal.

You may wish to use your data booklet.

1 mark (KU)

(d)Give a use for zinc metal.

1 mark (KU)

5.Copper can be extracted from its oxide by heating copper(II) oxide with hydrogen

gas. Water is also formed during the reaction.

(a)Write an equation, using symbols and formulae, for the reaction between copper(II) oxide and hydrogen gas.

There is no need to balance the equation.

1 mark (KU)

(b)Suggest the colour change which would be seen in the copper(II) oxide during the reaction.

1 mark (PS)

(c)Suggest why calcium cannot be extracted from its oxide by heating with hydrogen gas.

1 mark (PS)

6.Aluminium powder reacts with dilute sulphuric acid.

2Al(s) + 3H2S04(aq) A12(SO4)3 (aq) + 3H2(g)

(a)Circle the formula for the salt in the above equation.

1 mark (PS)

(b) Calculate the mass of hydrogen produced when 1.35g of aluminium reacts with dilute sulphuric acid.

2 marks (KU)

7.Bones are formed when calcium ions and phosphate ions combine to form insoluble calcium phosphate, Ca,(P04)2.

This reaction can be reproduced in the laboratory by adding a solution of calcium chloride to a solution of sodium phosphate.

3Ca2+(aq) + 6C1-(aq) + 6Na+(aq) + 2P043-(aq)6Na+(aq) + 6C1-(aq) + (Ca2+)3(P043-)2(s)

(a)Circle the spectator ions in the above equation.

1 mark (KU)

(b)What technique could be used to remove the calcium phosphate from the mixture?

1 mark (PS)

(c)Calculate the percentage by mass of calcium in calcium phosphate, Ca3(PO4)2.

2 marks (KU)

8. Iron ore is a mixture of compounds. One of these is called siderite and has the composition:

iron / 48.3%
oxygen / 41.4%
carbon / 10.3%

Calculate the empirical formula of siderite.

2 marks (KU)

9.The uses of metals are related to their properties.

Metal

/ Density
(g/cm3) / Relative
strength / Relative electrical
conductivity
Aluminium / 2.7 / 1.0 / 3.8
Steel / 7.9 / 4.0 / 1.0
Copper / 8.9 / 2.5 / 5.9

Overhead electricity cables have a steel core surrounded by an aluminium sheath.

Using information from the table, suggest:

(a)an advantage of using aluminium rather than copper for the cable;

1 mark (PS)

(b)why the cables have a steel core.

1 mark (PS)

10. The percentage of oxygen in air can be determined by reacting the oxygen with copper. The air is passed backwards and for yards over the heated copper.

Calculation:

Percentage of oxygen in air = reduction in volume of air x 100

volume of air at start of experiment

The following is taken from a pupil's lab book.

volume of air at start of experiment=60.0 cm3

volume of gas at end of experiment=47.5 cm3

(a)Calculate the percentage of oxygen in the sample of air. Show your working clearly.

1 mark (PS)

(b)Suggest a reason why the air is passed backwards and forwards over the

heated copper.

1 mark (PS)

(c)Suggest a reason whycarbon cannot be used in place of the copper.

1 mark (PS)

11.Titanium compounds have many uses.

(a) (i) Warships can produce a smokescreen by reacting titanium(IV)chloride with water:

TiCI4 (l) + H2O(l)Ti2(s) + HC1(g)

Balance this equation.

1 mark (KU)

(ii) Titanium(IV) chloride is a liquid at room temperature.

What type of bonding does this suggest is present in titanium(IV) chloride?

1 mark (PS)

(b) Titanium(IV) oxide (TiO2) is used as a white pigment in paint.

Calculate the percentage by mass of titanium in TiO2.

(Relative atomic mass of titanium = 48)

Show your working clearly.

2 marks (KU)

12.Some metals are found uncombined in the Earth's crust but others have to be extracted from their ores.

(a)Place the following metals in the correct space in the table.

lead, magnesium, mercury

You may wish to use the data booklet to help you.

Metal / Method of Extraction
using heat alone
using heat and carbon
electrolysis of molten compound

(b) Iron is extracted by reacting iron(III) oxide with carbon monoxide.

(i)Name the type of industrial plant where iron is extracted.

1 mark (KU)

(ii)The overall reaction taking place during the extraction of iron is given by the equation:

Fe2O3 + 3CO 2Fe + 3CO2

Calculate the mass of iron, in tonnes, which is produced from 1600 tonnes of iron(III) oxide.

Show your working clearly.

2 marks (KU)

Topic 11 Homework - Metals