National 5PhysicsSQAExam QuestionsProperties Of MatterSpecific Latent Heat

Specific Latent Heat (SQA National 5 Physics): Exam Questions

Exam code: X857 75

12 mins8 questions
1
Sme Calculator1 mark

The minimum energy required to melt 3.5 kg of ice at its melting point into water at the same temperature is

  • 1.5 cross times 10 to the power of 4 text  J end text

  • 1.2 cross times 10 to the power of 6 text  J end text

  • 7.9 cross times 10 to the power of 6 text  J end text

  • 1.2 cross times 10 to the power of 9 text  J end text

  • 7.9 cross times 10 to the power of 9 text  J end text

Choose your answer

21 mark

Two substances X and Y are both solid at 20 °C.

The substances have the same mass and are supplied with the same amount of energy per second.

The graph shows how the temperature of each substance varies with time.

Line graph showing temperature against time in seconds. Two lines, X and Y, rise then plateau, with X higher than Y, both sharply increase nearing 300 seconds.

A student uses information from the graph to make the following statements:

I The specific heat capacity of the solid substance X is greater than that of the solid substance Y.

II Substance X changes state at a higher temperature than substance Y.

III The specific latent heat of fusion of substance X is greater than that of substance Y.

Which of these statements is/are correct?

  • I only

  • I and II only

  • III only

  • II and III only

  • I, II and III

Choose your answer

3
Sme Calculator1 mark

Heat from the Sun melts 1.6 kg of ice in 40 minutes.

The minimum heat energy required to change 1.6 kg of ice at 0 °C into water at 0 °C is:

  • 6.7 cross times103 J

  • 1.3 cross times104 J

  • 2.1 cross times105 J

  • 5.3 cross times105 J

  • 3.6 cross times106 J

Choose your answer

41 mark

A solid substance is placed in an insulated container and heated.

The graph shows how the temperature T of the substance varies with time t.

Graph with stepped line from point P. Line descends to R, ascends to S, flat to T, and ascends again to U. Axes labelled T (vertical) and t (horizontal).

To calculate the specific latent heat of fusion of the substance a student would use the time from section

  • PQ

  • QR

  • RS

  • ST

  • TU

Choose your answer

51 mark

A solid substance is placed in an insulated container and heated.

The graph shows how the temperature T of the substance varies with time t.

Line graph with time (t) on x-axis and temperature (T) on y-axis. Graph shows varying slopes: PQ incline, QR flat, RS steep, ST flat, TU incline.

To determine the specific latent heat of vaporisation of the substance, a student would use the time from section

  • PQ

  • QR

  • RS

  • ST

  • TU

Choose your answer

6
Sme Calculator3 marks

Bottles used for feeding babies require sterilising before use.

For one design of bottle, a microwave oven is used to heat water in the bottle. This produces steam, which sterilises the bottle.

Open microwave with a baby bottle inside, set to 3:00 minutes on the digital display.

To sterilise the bottle, 0.020 kg of water is placed in the base of the bottle, before being heated in the microwave oven.

The initial temperature of the water is 6.3 °C.

During heating, 0.014 kg of water is changed to steam.

Calculate the energy required to change 0.014 kg of water at its boiling point to steam.

How did you do?

71 mark

A block of wax is initially in the solid state.

The block of wax is then heated.

The graph shows how the temperature of the wax changes with time.

Graph showing temperature increase over time. Starts at 20°C, rises to 40°C, 70°C, and 80°C at intervals of 30, 60, 90, and 120 minutes.

The melting point of the wax is

  • 0 °C

  • 20 °C

  • 40 °C

  • 70 °C

  • 80 °C

Choose your answer

83 marks

A student carries out a experiment, using the apparatus shown, to determine a value for the specific latent heat of vaporisation of water.

Diagram of a beaker with water at 100°C on a balance, featuring a thermometer, immersion heater, joulemeter, and power supply.

Describe how this apparatus would be used to determine a value for the specific latent heat of vaporisation of water.

Your description must include:

  • measurements made

  • any necessary calculations

How did you do?