The three states of matter

A teacher had a conical flask containing a gas.

How are the particles arranged in a gas?

Tick (✓) one box.

Particles are all touching each other.

Particles are arranged in a pattern.

Particles are arranged randomly.

How do the particles move in a gas?

Tick (✓) one box.

Particles move at the same speed.

Particles move in circular paths.

Particles move randomly.

The teacher demonstrated how gas pressure varies with temperature.

Figure 1 shows the apparatus used.

The Bunsen burner transferred thermal energy to the water.

The change in thermal energy of the water was 31 500 J.

The mass of water in the beaker was 0.25 kg.

Calculate the temperature increase of the water.

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

Use the equation:

When the temperature of the gas in the conical flask increased, the gas pressure in the conical flask increased.

How did increasing the temperature affect the mean speed of the gas particles?

How did increasing the temperature affect the mean kinetic energy of the gas particles?

Substances can exist in different states of matter.

The states of matter are solid, liquid and gas.

A substance has a melting point of – 7 °C and a boiling point of 59 °C.

A student purified a sample of water by distillation.

Figure 1 shows the apparatus.

Name the processes occurring at A, B, and C in Figure 1.

Choose answers from the box.

A

B

C

The student wanted to collect as much pure water as possible from the sample.

Some water was lost as steam from the end of the delivery tube.

Suggest one improvement to the apparatus to change more of the steam to water.

The water collected in the test tube is pure water.

Which statement is true for pure water?

Tick () one box.

Pure water boils at exactly 100 °C.

Pure water contains only one type of atom.

Pure water has a range of pH values.

Which two of the following are pure substances in chemistry?

Tick () two boxes.

Air

Carbon dioxide

Crude oil

Oxygen

Salt solution

Sea water is a mixture.

Figure 6 represents water as a solid.

Describe two limitations of Figure 6 as a model of a solid.

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

Figure 4 shows the apparatus.

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 2 shows the results.

Give one conclusion from the results.

Use the Physics Equations Sheet to answer questions 02.5 and 02.6.

Which equation links density (ρ), mass (m) and volume (V)?

Tick (✓) one box.

ρ = m × V

ρ = m × V³

The density of the wooden block was 0.85 g/cm³.

The mass of the wooden block was 30.6 g.

Calculate the volume of the wooden block in cm³.

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?

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The density decreases

The density stays the same

The density increases

Give a reason for your answer.

Different substances change state at different temperatures.

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

What is the state of sodium at 90 °C?

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Gas

Liquid

Solid

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 cm³ 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:

and

Use Figure 4.

Boiling point using 15 g of sodium chloride ________________ °C

Boiling point using 30 g of sodium chloride ________________ °C

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:

energy for the change of state = mass × specific latent heat of vaporisation

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?

Tick (✓) one box.

The kinetic energy of the particles will decrease.

The particles will hit each other less often.

The particles will move faster.

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.

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.

Matter can exist in different states.

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

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.

This question is about solids and liquids.

Describe two ways the arrangement of particles in a solid is different from the arrangement of particles in a liquid.

You should answer in terms of the particle model.

Liquid water can freeze to form solid ice.

Grit is spread on roads to reduce the formation of ice.

Grit contains a mixture of salt and sand.

Explain why less ice is formed when salt is spread on roads.

Figure 10 shows the mass of ice melted by 1 kg of grit at different temperatures.

Draw a line of best fit on Figure 10.

Predict the mass of ice that 1 kg of grit would melt at −20 °C

Use Figure 10.

Describe the effect of changing temperature on the mass of ice that 1 kg of grit can melt.

Use Figure 10.

Grit is spread on roads when low temperatures are expected.

Some roads are built with temperature sensors in the surface.

The sensors indicate when to spread grit on the roads.

Suggest one advantage of having temperature sensors in roads rather than relying on weather forecasts.

This question is about solids and liquids.

Describe two ways the arrangement of particles in a solid is different from the arrangement of particles in a liquid.

You should answer in terms of the particle model.

Liquid water can freeze to form solid ice.

Grit is spread on roads to reduce the formation of ice.

Grit contains a mixture of salt and sand.

Explain why less ice is formed when salt is spread on roads.

Figure 1 shows the mass of ice melted by 1 kg of grit at different temperatures.

Draw a line of best fit on Figure 1.

Predict the mass of ice that 1 kg of grit would melt at −20 °C

Use Figure 1.

Describe the effect of changing temperature on the mass of ice that 1 kg of grit can melt.

Use Figure 1.

Grit is spread on roads when low temperatures are expected.

Some roads are built with temperature sensors in the surface.

The sensors indicate when to spread grit on the roads.

Suggest one advantage of having temperature sensors in roads rather than relying on weather forecasts.