Properties of metals & alloys

This question is about metals.

Complete the sentence.

Choose the answer from the box.

Iron is extracted from iron oxide by reduction with carbon.

Why is iron extracted by reduction with carbon?

Tick () one box.

Aluminium is extracted by the electrolysis of aluminium oxide.

Figure 8 shows the apparatus used to extract aluminium.

The mixture of aluminium oxide and cryolite has a lower melting point than aluminium oxide alone.

Why is the melting point lowered?

Tick () one box.

After some time, the positive electrodes need to be replaced.

Why must the positive electrodes be replaced?

Tick () one box.

Aluminium can be mixed with other metals to form alloys.

How does the hardness of an alloy of aluminium compare with the hardness of pure aluminium?

Tick () one box.

Aluminium can form an alloy with silver.

Figure 9 shows how the melting point of the alloy changes with the percentage (%) of silver in the mixture.

Describe how the melting point of the alloy changes as the percentage of silver in the mixture increases.

Use data from Figure 9.

This question is about metals.

Iron is extracted from iron oxide by reduction with carbon.

Why can iron be extracted by reduction with carbon?

Answer in terms of reactivity.

Aluminium is extracted by the electrolysis of aluminium oxide.

Figure 4 shows the apparatus used to extract aluminium.

Explain why a mixture of aluminium oxide and cryolite is used as the electrolyte instead of only aluminium oxide.

Oxygen gas is produced at the positive electrode.

Write a balanced half equation for the production of oxygen at the positive electrode.

Chromium is extracted by reacting chromium oxide with aluminium.

The equation for the reaction is:

Which substance in the equation is reduced?

Table 3 shows the relative cost of extracting equal masses of aluminium, chromium and iron.

Give one reason for the difference in the cost of extracting aluminium and iron.

Use Table 3.

Give one reason for the difference in the cost of extracting aluminium and chromium

Use Table 3.

Metals are mixed together to form alloys.

Explain why alloys are harder than pure metals.

This question is about bonding and structures.

Figure 10 represents two models of sodium chloride.

Give two limitations of model A compared with model B.

Aluminium sulfate consists of the ions:

What is the formula of aluminium sulfate?

Metals have metallic bonding.

Suggest one reason why aluminium metal conducts electricity better than sodium metal.

Silicon dioxide and the polymer poly(ethene) are solid substances.

Compare silicon dioxide with the polymer, poly(ethene).

Answer in terms of structure and bonding.

Copper is a useful metal.

Figure 11 shows the mass of copper produced between 1900 and 2010.

Give two conclusions that can be made from Figure 11.

Mixtures of copper and zinc are heated to produce alloys.

Figure 12 represents the structures of pure copper and of an alloy of copper and zinc.

Explain why the alloy of copper and zinc is harder than pure copper.

Use Figure 12.

A 5.25 g sample of an alloy of copper and zinc contains 13.5% zinc by mass.

Calculate the mass of copper in the 5.25 g sample.

Give your answer to 3 significant figures.

Copper is a useful metal.

Figure 1 shows the mass of copper produced between 1900 and 2010.

Give two conclusions that can be made from Figure 1.

Mixtures of copper and zinc are heated to produce alloys.

Figure 2 represents the structures of pure copper and of an alloy of copper and zinc.

Explain why the alloy of copper and zinc is harder than pure copper.

Use Figure 2.

A 5.25 g sample of an alloy of copper and zinc contains 13.5% zinc by mass.

Calculate the mass of copper in the 5.25 g sample.

Give your answer to 3 significant figures.

Copper bromide solution is electrolysed using inert electrodes. Figure 11 shows the apparatus.

Which particles carry the electrical charge through the metal wire? Tick (✓) one box.

There are four ions in copper bromide solution:

• Cu²⁺

• Br^–

• H⁺

• OH^–

Two of these ions are formed when a water molecule breaks down. The symbol equation when a water molecule breaks down is:

Complete the word equation for the breakdown of a water molecule.

Copper ions and bromide ions carry the electrical charge through the solution. The formula of a copper ion is Cu²⁺ The formula of a bromide ion is Br^– What is the formula of copper bromide? Tick (✓) one box.

Explain why copper ions (Cu²⁺) move to the negative electrode.

Complete the sentence. Choose the answer from the box.

At the negative electrode copper metal is produced when the

What happens to the mass of the negative electrode during electrolysis? Tick (✓) one box.

There are four ions in copper bromide solution:

• Cu²⁺

• Br^–

• H⁺

• OH^–

What is produced at the positive electrode when copper bromide solution

Tick (✓) one box.

This question is about structure and properties.

Which pair of substances both contain atoms in hexagonal rings? Tick (✓) one box.

Explain why the structure of copper allows the conduction of thermal energy.

Explain why copper oxide (CuO) has a high melting point.

Explain why water (H₂O) has a low melting point.

This question is about structure and bonding. Figure 6 represents part of the structure of silicon dioxide.

What type of structure is silicon dioxide? Tick (✓) one box.

Each oxygen atom forms two bonds. What is the number of bonds formed by each silicon atom? Use Figure 6.

Figure 7 represents part of a fullerene.

Complete the sentence. Choose the answer from the box.

Complete the sentence. Choose the answer from the box.

The fullerene molecule shown in Figure 7 is made from

What is the fullerene molecule shown in Figure 7 used for? Tick (✓) one box.

Figure 8 represents part of the structure of a polymer.

What holds the atoms together in a polymer chain? Tick (✓) one box.

Complete the sentence. Choose the answer from the box.

In Figure 8 the polymer chains are held together by

Figure 9 represents part of the structures of:

• magnesium metal

• a magnesium alloy.

Calculate the percentage of copper atoms in the alloy. Number of magnesium atoms in the alloy = Number of copper atoms in the alloy = Total number of atoms in the alloy =

Explain why the magnesium alloy is harder than magnesium metal. Use Figure 9.

This question is about elements and compounds.

Magnesium and oxygen react to produce magnesium oxide. Balance the equation for the reaction.

Suggest one safety precaution that should be taken when heating magnesium and oxygen.

Calculate the relative formula mass (M_r) of magnesium fluoride (MgF₂). Relative atomic masses (A_r): F = 19 Mg = 24

Argon is a noble gas. Explain why no product is formed when magnesium and argon are heated together.

Figure 10 shows a reactivity series.

Figure 10

Draw one line from each metal to the method used to extract that metal. Use Figure 10.

Metal Method used to extract that metal

A substance conducts electricity when it has charged particles that are free to move.

Figure 11 represents the structure of sodium chloride.

Explain why sodium chloride conducts electricity when molten but not when solid.

Figure 12 represents the structure of sodium metal.

Explain why sodium metal conducts electricity when solid.

This question is about structure and bonding.

Figure 5 represents part of a carbon molecule.

Name the type of carbon molecule in Figure 5.

Suggest one property that makes the carbon molecule in Figure 5 useful in nanotechnology.

An alloy of aluminium contains small amounts of other metals. Explain why other metals are added to aluminium.

Figure 6 represents part of the structure of a polymer.

Compare the bonding within the chains with the forces between the chains in this polymer.

This question is about elements and compounds.

Figure 8 shows a reactivity series.

Figure 8

Give the method and conditions used to extract metal Y from a compound of metal Y

Sodium reacts with titanium chloride (TiCl₄) to produce titanium.

Complete the equation. You should balance the equation.

The reaction between sodium and titanium chloride is a redox reaction. Write a half-equation to show that sodium is oxidised in this reaction.

108 g of aluminum reacts with 1.21 kg of copper chloride to produce copper. The equation for the reaction is:

Calculate the maximum mass of copper produced in grams (g). You should determine the limiting reactant. Relative atomic masses (A_r): Al = 27 Cu = 63.5 Relative formula masses (M_r): CuCl₂ = 134.5 AlCl₃ = 133.5

Limiting reactant is Mass of copper = g

Sodium metal and sodium chloride are both able to conduct electricity.

Describe how sodium metal conducts electricity.

Explain how sodium chloride can conduct electricity.

Carbon can exist in a number of different structures.

The first fullerene to be discovered was Buckminsterfullerene. What is the formula of Buckminsterfullerene? Tick (✓) one box.

Graphite is a form of carbon. Explain why graphite conducts electricity.

Steel is an alloy of iron and carbon.

Explain why steel is harder than iron.

Iron is alloyed with carbon and other metals to make stainless steel. A stainless steel fork contains 71.92% iron. Table 2 shows the mass of each element in the fork.

Calculate the mass of iron (X) in the fork.

This question is about elements and compounds.

Figure 5 shows the proportion of elements in the periodic table that are metals and non-metals.

Determine the percentage of the elements in Figure 5 that are metals.

Give two physical properties of metals.

Sodium reacts with chlorine to produce sodium chloride. Balance the equation for the reaction.

Figure 6 shows part of the structure of sodium chloride (NaC l).

What holds the particles together in sodium chloride? Use Figure 6. Tick (✓) one box.

Solid sodium chloride does not conduct electricity. Give two ways in which sodium chloride can be made to conduct electricity.

This question is about the extraction of aluminium.

An aluminium atom is represented as: 27 A l 13 Give the number of electrons and neutrons in the aluminium atom.

Aluminium is extracted by the electrolysis of a molten mixture of aluminium oxide and cryolite. Figure 1 shows the cell used for the electrolysis.

Aluminium is produced by the reduction of aluminium oxide (Al₂O₃). What is meant by the term reduction?

Oxygen is formed at the positive carbon electrodes. Explain why the positive carbon electrodes must be continually replaced.

A substance conducts electricity because of free moving, charged particles. What are the free moving, charged particles in a:

• carbon electrode (made from graphite)

• molten mixture of aluminium oxide and cryolite

• metal wire?

Molten mixture of aluminium oxide and cryolite

This question is about structure and bonding.

Figure 5 shows part of the structure and bonding in diamond.

Explain why diamond has a high melting point.

Figure 6 shows part of the structure and bonding in sodium chloride (NaCl).

Explain the conditions needed for sodium chloride to conduct electricity.

Figure 7 shows the structure of sodium.

Describe how sodium conducts thermal energy.