States of Matter (AQA GCSE Combined Science: Synergy: Life & Environmental Sciences): Exam Questions

Different substances change state at different temperatures.

Table 1 shows the melting points and boiling points of three substances.

Table 1

What is the state of sodium at 90 °C?

Complete the sentence.

Choose the answer from the box.

Sodium chloride is a liquid at _________°C.

A student investigated the boiling point of different concentrations of sodium chloride solutions.

Figure 3 shows the apparatus.

This is the method used.

1. Add 100 of water to a beaker.

2. Add 10 g of sodium chloride to the water.

3. Heat the beaker until the solution boils.

4. Record the boiling point of the solution.

5. Repeat steps 1 to 4 with different masses of sodium chloride.

Figure 4 shows the results.

Determine the difference between the boiling point of the solution using:

• 15 g of sodium chloride

and

• 30 g of sodium chloride

Use Figure 4.

Describe the pattern of the results in Figure 4.

Include data from Figure 4 in your answer.

The student heated water at its boiling point until all the liquid water changed to water vapour.

mass of water = 0.20 kg

specific latent heat of vaporisation of water = 2 260 000 J/kg

Calculate the energy required to change the liquid water into water vapour.

Use the equation:

Choose the unit from the box.

Boiling water can be used to cook food.

Food can be cooked in a pressure cooker.

Figure 5 shows a pressure cooker.

What will happen to the water particles as the temperature of the water increases?

The pressure inside the pressure cooker changes during heating.

Table 2 shows the boiling point of the water in the pressure cooker at different pressures.

Table 2

What happens to the boiling point of the water as the pressure in the pressure cooker increases?

Use Table 2.

Figure 6 shows a saucepan.

The boiling point of water in a saucepan is 100 °C.

Explain one advantage of using a pressure cooker instead of a saucepan to cook food.

Keys are usually made from metal.

Figure 3 shows a metal key.

Describe a method to determine the density of the metal the key is made from.

You should include the measuring instruments you would use.

Use the Physics Equations Sheet.

A manufacturer of keys buys metal as small solid cubes.

A solid metal cube has a density of 2.70 × kg/.

The cube has a mass of 0.0216 kg.

Calculate the surface area of the cube.

Use the Physics Equations Sheet.

Matter can exist in different states.

Table 7 shows the melting points and boiling points of four substances.

Table 7

Give the temperature at which nitrogen condenses.

Nitrogen gas is transported in cylinders at high pressure.

Figure 10 shows a cylinder containing nitrogen gas.

What causes the pressure on the inside walls of the gas cylinder?

Carbon dioxide sublimates.

What happens when carbon dioxide sublimates?

Use Table 7.

Solid carbon dioxide is used during the transport of frozen food.

Using solid carbon dioxide keeps the food cold for longer than using frozen water.

Suggest one other advantage of using solid carbon dioxide instead of using frozen water during the transport of frozen food.

The planet Saturn has a moon called Titan.

The surface temperature of Titan is −179.6 °C.

Features similar to rivers have been seen on Titan.

Which substance in Table 7 could be the liquid in the rivers on Titan?

Figure 11 shows a simple model which can be used to describe changes of state.

Give two limitations of using this model to describe changes of state.

Some water at 15 °C is heated until it all turns to steam at 100 °C.

The total energy supplied to the water is 1 320 000 J.

mass of water = 500 g

specific heat capacity of water = 4200 J/kg °C

Calculate the specific latent heat of vaporisation of water.

Use the Physics Equations Sheet.

[6 marks]

Heaters can be used to heat homes and gardens.

Gas heaters can be used to heat gardens.

The gas is stored in a container with a fixed volume.

Figure 10 shows a gas heater.

On a sunny day the burner is not lit.

The temperature of the gas in the container increases.

Complete Table 3.

Put one tick (✓) in each row.

Table 3

Figure 11 shows an electric heater.

The heater is filled with a liquid.

When the heater is switched on, the temperature of the liquid in the heater increases.

On one day, the starting temperature of the liquid was 15.0 °C.

The final temperature of the liquid was 57.5 °C.

What was the temperature change of the liquid?

Temperature change = _______ °C

The change in thermal energy of the liquid in the heater was 892 500 J.

What was the change in thermal energy of the liquid in kJ?

1000 J = 1 kJ

Change in thermal energy = _______kJ

On another day, the temperature change of the liquid was 45.0 °C.

The mass of liquid in the heater is 5.0 kg.

specific heat capacity of liquid = 4200 J/kg °C

Calculate the change in thermal energy of the liquid in the heater in joules.

Use the equation:

change in thermal energy = mass × specific heat capacity × temperature change

Change in thermal energy = ______J

The liquid in the heater was replaced with a new liquid.

The new liquid had a greater specific heat capacity.

What happened to the energy required to increase the temperature of the liquid in the heater by 1 °C?

Tick (✓) one box.

A student investigated how the density of a liquid affects the position of a wooden block floating in the liquid.

Figure 18 shows the apparatus.

Figure 18

This is the method used:

1. Put the wooden block in the beaker of liquid

2. Allow the wooden block to come to rest so that it is floating in the liquid

3. Measure the distance between the liquid surface and the bottom of the block

4. Repeat steps 1 to 3 with liquids of different densities

Give the independent variable in the investigation.

Give one control variable for the investigation.

Give one possible source of error when the student measured the distance between the liquid surface and the bottom of the block.

Table 6 shows the results.

Table 6

Give one conclusion from the results.

Use the Physics Equations Sheet to answer questions 08.5 and 08.6.

Which equation links density (), mass () and volume ()?

Tick (✓) one box.

The density of the wooden block was 0.85 g/.

The mass of the wooden block was 30.6 g.

Calculate the volume of the wooden block in .

Volume of wooden block =

Liquid C is water.

When liquid water is heated to its boiling point the water changes state.

What happens to the density of the liquid water as it changes state?

Tick (✓) one box.

• The density decreases

• The density stays the same

• The density increases

Give a reason for your answer.

Figure 6 shows an electric heater. This type of heater is filled with a liquid.

Figure 6

The heater contained 5.0 kg of water.

When the heater was switched on, the temperature of the water in the heater increased to 75 °C.

The change in thermal energy of the water was 1260 kJ.

specific heat capacity of water = 4200 J/kg °C

Calculate the starting temperature of the water in the heater.

Use the Physics equations sheet.

Starting temperature = ----------------°C

An identical heater contains 5.0 kg of oil instead of 5.0 kg of water.

specific heat capacity of oil = 1970 J/kg °C

specific heat capacity of water = 4200 J/kg °C

Explain the difference in the energy needed to cause the same temperature change in the oil and in the water.

Gas heaters may be used to heat gardens.

The gas is stored in a container with a fixed volume.

Figure 7 shows a gas heater.

Figure 7

On a sunny day the burner is not lit.

The temperature of the gas in the container increases.

Explain why the pressure inside the container changes.

A student investigated the heating of some wax.

This is the method used.

1. Put a cube of wax in a beaker.

2. Place the beaker on a heater connected to a joulemeter.

3. Turn on the heater.

4. When the wax begins to melt, turn on the joulemeter.

5. When all the wax has melted, record the reading shown on the joulemeter.

Figure 2 shows the arrangement.

The mass of the cube of wax was 0.15 kg.

The energy transferred to melt the wax was 31 500 J.

Calculate the specific latent heat of fusion of wax.

Use the equation:

Choose the unit from the box.

Specific latent heat of fusion = ________ Unit _________

Not all of the energy transferred by the heater was used to melt the wax.

What happened to the energy that was not used to melt the wax?

Which two of the following would increase the accuracy of the student's results?

The student continued to heat the wax after it had melted.

The student measured the temperature of the wax every 10 seconds.

Figure 3 shows how the temperature of the liquid wax varied with time.

What was the temperature change between 0 seconds and 80 seconds?

Between 0 seconds and 80 seconds, 3600 J of energy was transferred to the wax.

The mass of wax was 0.15 kg.

Calculate the specific heat capacity of the wax using the student's data.

Use your answer to Question 02.4 and the equation:

Specific heat capacity = ______________J/kg °C

In chemistry, a pure substance is a single element or compound.

Describe how measurements taken during a change of state can show if a substance is pure.

A student investigated the heating of some wax.

Method:

1. Put a cube of wax in a beaker.

2. Place the beaker on a heater connected to a joulemeter.

3. Turn on the heater.

4. When the wax begins to melt, turn on the joulemeter.

5. When all the wax has melted, record the reading shown on the joulemeter.

Figure 10 shows the arrangement.

The student made these measurements:

• mass of the cube of wax = 0.15 kg

• energy transferred to melt the wax = 33 kJ

Calculate the specific latent heat of fusion of wax using the student's measurements.

Use the Physics Equations Sheet.

Specific latent heat of fusion of wax =____________ J/kg

The student's value for specific latent heat of fusion is not accurate because some energy was dissipated to the surroundings.

Explain how the dissipation of energy affected the student's calculated value.

The student continued to heat the wax after it had melted. The student measured the temperature of the wax every 10 seconds.

Figure 11 shows how the temperature of the wax varied with time.

Between 0 seconds and 80 seconds, 4950 J of energy was transferred to the wax.

The mass of the wax was 0.15 kg.

Determine the specific heat capacity of the wax.

Use the Physics Equations Sheet.

Specific heat capacity = _____________J/kg°C

Density can be explained using the particle model.

What is the unit of density (ρ)?

Tick one box.

Figure 4 shows particles of the same substance in three states of matter

Use Figure 4 to explain why the solid has the highest density.

Complete the sentences.

Use answers from the box.

The particles in a gas are constantly moving.

The particles move___________________________ .

When the temperature of the particles in a gas is increased the particles have more ______________________ energy.

A gas is put into a closed container.

The container and the gas inside it are heated.

What will happen to the pressure inside the container?

A student investigated the specific heat capacity of metals.

Describe an experiment the student could do to measure the specific heat capacity of a metal.

The student calculated the specific heat capacity of four metals.

Table 7 shows the student's results.

Table 7

Use data from Table 7 to calculate the temperature change for copper. Use the correct equation from the Physics Equation Sheet.

Temperature change = ________________°C

What is the independent variable in the student's investigation?

Tick one box.

The student calculated the specific heat capacity of aluminium to be 2390 J/kg °C.

The 'true' specific heat capacity of aluminium is 900 J/kg °C.

Suggest why the student's result for aluminium is different from the 'true' value.

The teacher suggested that putting bubble wrap round the metal block would change the results.

How would using bubble wrap change the results?

Give a reason for your answer.

Figure 6 shows a simple model of the three states of matter

What is the correct equation to work out the density of a material?

A student explains density to his teacher using the particle model in Figure 6.

His teacher says there are limitations to the model.

Give two limitations of the particle model in Figure 6.

1. _________________________________________________________

2. _________________________________________________________

When the gas in a container with a fixed volume is heated, the pressure increases as the temperature increases.

Explain why the pressure increases.

Use the model in Figure 6 to help you.