Chemical cells & batteries

Cells contain chemicals that react to produce electricity.

A student investigated the voltage produced by four different cells.

Figure 3 shows the apparatus.

This is the method used.

1. Measure the voltage produced by the cell using metal A as the metal electrode.

2. Repeat using different metals as the metal electrode.

Table 2 shows the results.

Which substance could be used as the electrolyte in the cell in Figure 3 ?

Tick () one box.

Which metal A, B, C or D was copper?

Give one reason for your answer.

Use Figure 3 and Table 2.

Write the four metals A, B, C and D in order of reactivity.

Use Table 2.

A battery consists of several cells connected together in series.

Each cell has a voltage of 3.6 V.

Calculate the number of cells needed to make a battery of voltage 14.4 V.

Fuel cells can be used to power electric cars.

Complete the sentence.

Choose the answer from the box.

The overall reaction in a hydrogen fuel cell involves the oxidation of

Rechargeable cells can be recharged when an external electrical current is supplied.

Complete the sentence.

When an external electrical current is supplied to a rechargeable cell,

the chemical reaction is.

This question is about chemical cells.

A student connects four 1.5 V cells in series to make a battery.

What is the total voltage produced by the battery?

A chemical cell can be made using two different metals in contact with an electrolyte.

Figure 14 shows a chemical cell.

Which is a suitable electrolyte for a chemical cell?

Tick () one box.

A student made the hypothesis:

‘The voltage produced by a cell depends on the difference in the reactivity of metal A and metal B.’

Plan an investigation to test this hypothesis.

Your plan should produce valid results.

Use Figure 14.

A student investigated the voltage produced by different pairs of metal electrodes in a chemical cell.

Figure 6 shows the apparatus.

This is the method used.

1. Place a nickel electrode and an electrode made from a different metal (electrode A in 1.0 mol/dm³ sodium chloride solution.

2. Measure the voltage produced.

3. Repeat using different metals for electrode A.

Table 3 shows the results.

Write the symbols of the five metals in Table 3 in order of reactivity.

Justify your answer.

Most reactive Least reactive

The voltage produced by a chemical cell depends on the concentration of the electrolyte solution.

Plan an experiment to investigate how the voltage produced by a chemical cell varies with the concentration of the electrolyte solution.

The following substances are available:

• the metal electrodes in Table 3

• 1.0 mol/dm³ sodium chloride solution

• pure water.

Describe how a hydrogen fuel cell produces a potential difference.

This question is about zinc and compounds of zinc. A student produces pure crystals of zinc chloride by reacting zinc oxide with hydrochloric acid. The equation for the reaction is:

The student adds zinc oxide to hydrochloric acid until the zinc oxide is in excess. Give one observation that the student could make to show that the zinc oxide is in excess.

Why is excess zinc oxide used rather than excess hydrochloric acid?

Name one other compound that the student could add to hydrochloric acid to produce zinc chloride.

Describe how the student should obtain crystals of zinc chloride from a solution of zinc chloride.

Zinc chloride is also produced in a displacement reaction between zinc and copper chloride solution. The equation for the reaction is:

Complete the ionic equation for this reaction.

Why is zinc described as being oxidised in this reaction?

Zinc and copper can be used with another substance to produce electricity. Complete Figure 7 to show how zinc, copper and another substance can be used to light a lamp. Label:

• zinc

• copper

• the other substance used.

The symbol represents the lamp.

This question is about chemical cells and batteries.

Three different types of battery can be used to power a TV remote control.

Table 1 gives information about these batteries.

Give one advantage of each type of battery.

Nickel-metal hydride

Figure 3 shows a symbol printed on batteries.

This symbol shows that batteries should not be put in household waste.

Suggest why batteries should not be put in household waste.

Figure 4 shows a chemical cell.

The order of reactivity of three metals is shown below.

Which combination of metal electrodes would give the highest voltage in the chemical cell in Figure 4 ?

Tick (✓) one box.

The voltage produced by the cell in Figure 4 depends on the type of electrodes and the type of electrolyte.

Suggest one other factor that could affect the voltage produced.

Water is produced in a hydrogen fuel cell.

Complete the word equation to show the reaction that produces water in a hydrogen fuel cell.

This question is about chemical reactions and electricity.

Electrolysis and chemical cells both involve chemical reactions and electricity. Explain the difference between the processes in electrolysis and in a chemical cell.

A teacher demonstrates the electrolysis of molten lead bromide. Bromine is produced at the positive electrode. Complete the half equation for the production of bromine. You should balance the half equation.

Two aqueous salt solutions are electrolysed using inert electrodes. Complete Table 4 to show the product at each electrode.

Some students investigated the electrolysis of copper nitrate solution using inert electrodes. Figure 4 shows the apparatus.

The students investigated how the mass of copper produced at the negative electrode varied with:

• time

• current.

This is the method used.

1. Weigh the negative electrode.

2. Set up the apparatus shown in Figure 4.

3. Adjust the power supply until the ammeter shows a current of 0.3 A

4. Switch off the power supply after 5 minutes.

5. Rinse the negative electrode with water and allow to dry.

6. Reweigh the negative electrode.

7. Repeat steps 1 to 6 for different times.

8. Repeat steps 1 to 7 at different currents.

Some of the copper produced did not stick to the negative electrode but fell to the bottom of the beaker. Suggest how the students could find the total mass of copper produced.

The students plotted their results on a graph. Figure 5 shows the graph.

A student correctly concluded that the total mass of copper produced is directly proportional both to the time and to the current.

How do the results in Figure 5 support the conclusion that the total mass of copper produced is directly proportional to the time?

How do the results in Figure 5 support the conclusion that the total mass of copper produced is directly proportional to the current? Use data from Figure 5 in your answer.

Copper nitrate solution is blue. Suggest why the blue colour of the copper nitrate solution fades during the electrolysis.

Determine the number of atoms of copper produced when copper nitrate solution is electrolysed for 20 minutes at a current of 0.6 A Give your answer to 3 significant figures. Use Figure 5. Relative atomic mass (A_r): Cu = 63.5 The Avogadro constant = 6.02 10²³ per mole

This question is about chemical reactions and energy. Hydrogen reacts with oxygen to produce water. This reaction releases energy.

Complete the word equation for the reaction. [1 mark hydrogen + oxygen → ____________

Figure 3 shows a reaction profile for the reaction between hydrogen and oxygen.

What do the labels W, X, Y and Z represent? Choose answers from the box.

The reaction between hydrogen and oxygen is used in a hydrogen fuel cell. What is the reason for using this reaction in a fuel cell? Tick (✓) one box.

A student investigated the voltage produced by a chemical cell. The student used different metals as the electrodes in the cell. The metals used were:

• copper

• iron

• magnesium.

Which two metal electrodes would produce the greatest voltage when used in the chemical cell? Give one reason for your answer.

This question is about chemical cells and batteries. A student investigated the voltage produced by different chemical cells. Figure 7 shows the apparatus.

This is the method used.

1. Use cobalt metal as electrode X.

2. Record the cell voltage.

3. Repeat steps 1 and 2 using different metals as electrode X.

Suggest two variables the student should keep the same to make the investigation valid.

Table 1 shows the student’s results.

Write the three metals used for electrode X in order of reactivity. Use Table 1.

Copper is used as electrode X in Figure 7. Predict the voltage of this cell. Give one reason for your answer.

Describe how to make a 12 V battery using 1.5 V cells.

Which is the most suitable use for a non-rechargeable cell? Tick (✓) one box.

Hydrogen fuel cells or rechargeable cells can be used to power electric vehicles. Suggest one advantage and one disadvantage of using a hydrogen fuel cell compared with a rechargeable cell.

Advantage of hydrogen fuel cell

Disadvantage of hydrogen fuel cell

This question is about chemical cells. A student investigated the voltage produced by different chemical cells. Figure 9 shows the apparatus.

This is the method used.

1. Use cobalt as electrode X.

2. Record the cell voltage.

3. Repeat steps 1 and 2 using different metals as electrode X.

Suggest two control variables used in this investigation.

Table 4 shows the student’s results.

Write the six metals used for electrode X in order of reactivity. Use Table 4. Justify your order of reactivity.

Which of the following pairs of metals would produce the greatest voltage when used as the electrodes in the cell? Use Table 4. Tick (✓) one box.

Hydrogen fuel cells can be used to power different forms of transport. Some diesel trains are being converted to run on hydrogen fuel cells. A newspaper article referred to the converted trains as the new ‘steam trains’. Suggest why.

Chemical reactions can produce electricity.

Figure 13 shows a simple cell.

Which of these combinations would not give a zero reading on the voltmeter in Figure 13 ?

Tick one box.

Electrode A
Electrode B
Electrolyte

Alkaline batteries are non-rechargeable.

Why do alkaline batteries eventually stop working?

Why can alkaline batteries not be recharged?

Hydrogen fuel cells and rechargeable lithium-ion batteries can be used to power electric cars.

Complete the balanced equation for the overall reaction in a hydrogen fuel cell.

Table 7 shows data about different ways to power electric cars.

Evaluate the use of hydrogen fuel cells compared with rechargeable lithium-ion batteries to power electric cars.

Use Table 7 and your own knowledge.

Chemical reactions can produce electricity.

Figure 2 shows a simple cell.

Which of these combinations would not give a zero reading on the voltmeter in Figure 2 ?

Tick one box. Electrode A Electrode B Electrolyte

Alkaline batteries are non-rechargeable.

Why do alkaline batteries eventually stop working?

Why can alkaline batteries not be recharged?

Hydrogen fuel cells and rechargeable lithium-ion batteries can be used to power electric cars.

Complete the balanced equation for the overall reaction in a hydrogen fuel cell.

Table 1 shows data about different ways to power electric cars.

Evaluate the use of hydrogen fuel cells compared with rechargeable lithium-ion batteries to power electric cars. Use Table 1 and your own knowledge.