IGCSEPhysicsEdexcelTopic Questions5. Solids, Liquids & Gases5.2 Changes of State

Changes of State (Edexcel IGCSE Physics)

Topic Questions

DownloadView
Easy
Medium
Hard
Easy
Medium
Hard
1a4 marks

A student investigates ice, water and steam.

She heats up a sample of ice.

When it has all melted, she carries on heating until the water has all boiled to steam. 

Complete the diagram to show how the particles are arranged in ice, water and steam.

One particle in each box has been drawn for you. 

screenshot-2022-09-27-at-12-18-59

How did you do?

1b3 marks

Complete the table by describing how the particles move in ice, water and steam.

screenshot-2022-09-27-at-12-23-41

How did you do?

Did this page help you?

26 marks

The change in thermal energy, ΔQ is given by the equation:

straight capital delta Q space equals space m c straight capital delta T

State the definition of the following variables and an appropriate unit for each:

 
(i)
m
(2)
(ii)
c
(2)
(iii)
ΔT
(2)

How did you do?

Did this page help you?

3a2 marks

The particles in the different states of matter behave differently. 

Draw a straight line linking each state of matter with the description of its particles. 

screenshot-2022-09-27-at-13-01-13

How did you do?

3b4 marks

Hot water from the power station is sprayed into the cooling tower, as shown in the diagram. As it falls through the air, some of the hot water evaporates.

The rest of the water is collected and returned as cold water to the power station.

13-4-1b

Complete the sentences by circling the correct words

The temperature of the particles is directly / inversely proportional to their average kinetic / potential energy

Energetic particles turn into liquid / gas as they leave the surface of the liquid / gas

Gas particles have a higher / lower average kinetic / potential energy than the particles in the liquid, therefore, they move faster / slower

The average kinetic / potential energy, and therefore temperature, of the remaining particles in the liquid increases / decreases

How did you do?

Did this page help you?

4a3 marks

Describe the arrangement of the particles in a solid, a liquid and a gas.

How did you do?

4b3 marks

Describe the motion of the particles in a solid, a liquid and a gas.

How did you do?

4c1 mark

During a dry day, a puddle on a road dries up and disappears.

State the name of the process which causes this to happen.

How did you do?

4d1 mark

Describe one change in the weather that would cause the puddle to dry up more quickly.

How did you do?

Did this page help you?

5a1 mark

A substance is cooled. The graph below shows how the temperature changes with time.

5-2-q5a-e-cooling-curve

Which of the following correctly describes the physical change happening between X and Y on the graph?

  • The gas is cooling

  • The liquid is freezing

  • The gas is condensing

  • The liquid is cooling

Choose your answer

5b1 mark

A solid substance is heated at a constant rate. The graph shows how its temperature changes with time.

5-2-q5b-e-changes-of-state-heating-graph

Which of the following regions of the graph represents the time when the substance is partially a liquid and partially a gas?

  • V to W

  • W to X

  • X to Y

  • Y to Z

Choose your answer

5c3 marks

A student pours 0.20 kg of water into a beaker. A thermometer placed in the water has a reading of 25 °C.

The temperature is monitored as ice is added to the beaker until the thermometer reads 0 °C.

(i)
State the equation linking energy transferred, mass, specific heat capacity and change in temperature.
(1)
(ii)
Calculate the amount of energy transferred by the water as it cools from 25 °C to 0 °C.
The specific heat capacity of water is 4200 J/kg °C.
(2)
 
energy transferred = .............................. J

How did you do?

Did this page help you?

1a6 marks

These are some observations about samples of ice, water and steam. 

screenshot-2022-09-27-at-13-17-47

Explain each of the observations in terms of the arrangement and motion of the particles.

How did you do?

1b4 marks

Ethyne is a substance that is a gas at room temperature. At a temperature of -81 °C, ethyne can exist as a solid, a liquid or a gas. 

This temperature is called the triple point of ethyne. 

 
(i)
Complete the table by giving the missing temperatures.
(2)
screenshot-2022-09-27-at-13-06-29
(ii)
State what happens to the average kinetic energy of the gas molecules as the temperature is lowered from room temperature to the triple point of ethyne. 
(1)
 
(iii)
State what happens to the volume of an ethyne molecule when the gas changes to a solid at the triple point. 
(1)
 

How did you do?

Did this page help you?

2a3 marks

The picture shows a runner. 

screenshot-2022-09-27-at-13-22-03

As he runs, the runner gets hot. To avoid overheating, his body sweats. As the sweat evaporates, it cools his body. 

Use ideas about particles to explain why evaporation leads to cooling. 

How did you do?

2b4 marks

At the end of a long race, runners are given a shiny foil sheet to wear.

This stops them cooling down too quickly. 

screenshot-2022-09-27-at-13-27-58
 
(i)
Suggest why a runner might cool down too quickly if he does not wear a foil sheet.
(2)
(ii)
Explain how the foil sheet reduces heat loss. 
(2)

How did you do?

Did this page help you?

3a2 marks

A mass of 250 g of water is needed to make a cup of tea. An input of 85 kJ is needed to boil the water. 

Calculate the initial temperature of the water. 

Specific heat capacity of water = 4200 J kg–1 K–1.

 
initial temperature = ............................. ºC

How did you do?

3b2 marks

Most kettles take between 1 to 4 minutes to boil, depending on the amount of water.

If water had a lower specific heat capacity, state two differences this would make to boiling water in an electric kettle.

How did you do?

Did this page help you?

4a1 mark

This question is about determining the specific heat capacity of aluminium.

A block of aluminium has a mass of 0.32 kg and an initial temperature of 30 °C. The block is heated until it has a temperature of 75 °C. This takes 2.5 minutes.

What is the average thermal power transferred away from the metal block? 

You may take the specific heat capacity of aluminium to be 900 J kg−1 K−1.

  • 56 W

  • 75 W

  • 86 W

  • 112 W

Choose your answer

4b6 marks
A student wants to determine the specific heat capacity of aluminium. They use the apparatus shown in the diagram.

 

5-2-4b-h-aluminium-specific-heat-capacity

A piece of string is tied to the aluminium block so it can be transferred from the boiling water to the cold water.

Describe how this apparatus could be used to determine the specific heat capacity of aluminium.

Your answer should include:

    • any additional pieces of equipment required
    • how to obtain the necessary measurements
    • how the measurements should be used to calculate the specific heat capacity of aluminium

How did you do?

Did this page help you?

5a7 marks

The specific heat capacity of water can be measured using the apparatus in the diagram:

5-2-q5a-h-immersion-heater-practical

(i)
State the variables which need to be measured to calculate the specific heat capacity of water.
(3)
(ii)
Explain how you would measure one of these variables.
(1)
(iii)
State three ways the experiment could be improved. 
(3)

     

How did you do?

5b4 marks

The temperature of the water is recorded every minute for 6 minutes.

Time (mins) Temperature (°C)
0 20
1 31
2 39
3 40
4 61
5 70
6 82

 

Plot a graph of the results.

graph-paper

How did you do?

5c3 marks
(i)
Circle the anomalous point on the graph.
(1)
(ii)
State what the student should do with the anomalous reading.
(2)

How did you do?

5d2 marks

Predict the temperature at: 

(i)
8 minutes
(1)
(ii)
9 minutes
(1)

How did you do?

Did this page help you?

1a4 marks

A cooling tower is designed to transfer thermal energy away from a power station.

13-4-1a

© Copyright Alan Murray-Rust

Thermal energy from the power station warms the air inside the cooling tower. Air enters through holes at the bottom of the cooling tower and leaves through the top.

13-4-1a2

Explain why the air moves as shown by the arrows.

How did you do?

1b3 marks

Hot water from the power station is sprayed into the cooling tower, as shown. As it falls through the air, some of the hot water evaporates. The rest of the water is collected and returned as cold water to the power station.

13-4-1b

Explain how evaporation cools the water.

How did you do?

Did this page help you?

2a1 mark

James Dewar was a scientist who investigated liquid oxygen.

He discovered that the boiling point of liquid oxygen is –183 °C.

Convert –183 °C to a temperature on the Kelvin scale.

temperature = ....................... 

How did you do?

2b3 marks

Use ideas about particles to describe the changes that happen when a liquid boils to form a gas.

How did you do?

Did this page help you?

3a2 marks

Temperature can be measured using different scales.

Complete the table by inserting the missing temperatures. 

screenshot-2022-09-27-at-10-11-37

How did you do?

3b5 marks

Some students measure the volume of a sample of gas at different temperatures.

The table below shows their results. 

screenshot-2022-09-27-at-10-13-28
 
(i)
Draw a graph to show how the volume of gas varies with temperature. 
(3)
screenshot-2022-09-27-at-10-14-46
 
(ii)
Circle the anomalous point on your graph. 
(1)
 
(iii)
Use your graph to find the temperature of the gas when its volume is zero. 
(1)
 
temperature = ..................................... °C

How did you do?

Did this page help you?

4a3 marks

The rate of evaporation of a liquid can be influenced by various factors.

State three factors that affect the rate of evaporation.

How did you do?

4b2 marks

A person falls into a lake. When they climb out they feel cold due to the evaporation of the water from their body.

Explain why evaporation makes the person feel cold.

How did you do?

4c3 marks

The person makes a cup of tea to get over the shock of falling into the water.

They heat water over a stove for 6 minutes until it boils, and continue to heat it for a further 3 minutes.

Explain how the temperature of the water changes during the 9 minutes of heating.

How did you do?

Did this page help you?

5a3 marks

A lidded beaker contains water vapour.

Describe the movement of the particles in: 

(i)
A solid box
(1)
(ii)
The water vapour
(2)

How did you do?

5b4 marks

The water vapour is allowed to cool and the temperature is taken at regular intervals.

Sketch a graph to show the change in temperature with time.

How did you do?

5c2 marks

Explain what is meant by the specific heat capacity of a substance.

How did you do?

5d3 marks

A mass of 170 g of water is needed to make a cup of masala chai tea which is brewed at an optimum temperature of 80 ºC. The water is boiled in a kettle from a temperature of 55 ºC from the tap.

The specific heat capacity of water = 4200 J kg–1 K–1.

Calculate the energy needed to boil the water to make a cup of masala chai tea.

energy needed = ....................................... J

How did you do?

Did this page help you?