National 5 Physics

Revision for Matter Test

Specific Heat Capacity

Latent Heat

Gas Laws and Kinetic Model

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Specific Heat Capacity and Latent Heat Multiple Choice Questions Q1. The units of specific heat capacity are A Jkg°C B J-1kg°C C Jkg-1°C D Jkg°C-1 E Jkg-1°C-1 Q2. A kettle of power p is used to heat water to boiling in time t. Assuming

all the required quantities can be measured which of the following is/are true?

I The energy gained by the water can be calculated using

𝐸 = 𝑚𝑐Δ𝑇.

II The energy gained by the water can be calculated using 𝐸 = 𝑝𝑡.

III The calculated value for the energy gained by the water using 𝐸 = 𝑝𝑡 will be smaller than the actual gain unless the energy lost to the environment is taken into account.

A I only

B II only C III only D I and II only E I, II and III Q3. Milk of mass 250g absorbs 48 kJ of energy during the heating in a

microwave. The specific heat capacity of milk is 3900 Jkg-1°C-1. The temperature rise in the milk is A 0.049°C B 0.49°C C 4.9°C D 49°C E 490°C

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Q4. A 2000W kettle raises the temperature of 0.50kg of water by 75°C in

90seconds. How much energy is lost to the environment during heating? A 0kJ B 23kJ C 160kJ D 180kJ E 6800kJ Q5. Substance A has a higher specific heat capacity than substance B. Which

of the following statements is/are true?

I If the masses of A and B are the same, adding the same quantity of heat will cause the same temperature rise in each substance.

II The energy required to raise the temperature of 1kg of substance

A by 1°C has the same value as its specific heat capacity. III The same heat energy is added to samples of substances A and B

This gives the same temperature rise in both samples. The mass of sample A must be greater than the mass of sample B.

A I only B II only C III only D I and II only E II and III only

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Q6. Five students each carry out an experiment to determine the specific heat capacity of copper. The setup used by each student is shown.

The student with the setup that would allow the most accurate value for the specific heat capacity of copper to be determined is A student 1 B student 2 C student 3 D student 4 E student 5.

Copper Block

immersion heater

Power Supply

thermometer Student 1

immersion heater

insulation

Student 2 thermometer

Power Supply

thermometer

immersion heater

Student 3

Power Supply

immersion heater

Student 4 thermometer

Power Supply

thermometer

immersion

insulation

Student 5

Power Supply

Copper Block

Copper Block

Copper Block

Copper Block

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Q7. The minimum amount of energy required to change 0·5 kg of water at its boiling point into steam at the same temperature is

A 2·09 × 103 J B 1·67 × 105 J C 3·34 × 105 J D 1·13 × 106 J E 2·26 × 106 J.

Q8. A solid substance is placed in an insulated flask and heated continuously

with an immersion heater. The graph shows how the temperature of the substance in the flask changes in time.

At 5 minutes the substance is a A solid B liquid C gas D mixture of solid and liquid E mixture of liquid and gas.

Q9. The specific latent heat of fusion of a substance is the energy required to

A melt 1 kg of the substance at its melting point B evaporate 1 kg of the substance at its boiling point C change the state of the substance without changing its

temperature D change the temperature of the substance without changing its

state E change the temperature of 1 kg of the substance by 1 °C.

0

temperature (°C)

2 6 10 30 time (minutes)

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Q10. A block of ice of mass 1·5 kg is placed in a room. The temperature of the block is 0°C. The temperature of the room is 20°C. The minimum energy required to melt the ice is A 0·63 × 105 J B 1·25 × 105 J C 1·88 × 105 J D 5·01 × 105 J E 6·26 × 105 J

Q11. A heater is immersed in a substance. The heater is then switched on.

The graph shows the temperature of the substance over a period of time.

Which row in the table identifies the sections of the graph when the substance is changing state?

Solid to liquid Liquid to gas

A QR TU

B QR ST

C PQ RS

D PQ TU

E ST QR

P

R Q

U T S

Time (s)

Tem

per

atu

re (

°C)

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Q12. A heater transfers energy to boiling water at the rate of 1130 joules every second. The maximum mass of water converted to steam in 2 minutes is

A 1.0 × 10−3kg B 6.0 × 10−2kg C 0.41 kg D 17 kg E 32 kg.

Q13. 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.

The melting point of the wax is A 0°C B 20°C C 40°C D 70°C E 80°C.

time (minutes)

Tem

per

atu

re (

°C)

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Specific Heat Capacity and Latent Heat Extended Response Questions Q1. A washing machine fills with

water at a temperature of 15°C. The water is heated by a heating element.

The mass of water in the machine it 6.0kg. Calculate the minimum energy required to heat the water to 40°C. (3)

Q2. A manufacturer has developed an iron

with an aluminium sole plate. A technician has been asked to test the iron.

The technician obtains the following data for one setting of the iron.

Starting temperature of sole plate: 24 °C Operating temperature of the sole plate: 200 °C Time for iron to reach the operating temperature: 35 s Power rating of the iron: 1·5 kW Operating voltage: 230 V Specific Heat Capacity of Aluminium: 902 Jkg-1 °C-1

a. Calculate how much electrical energy is supplied to the iron in this time.

(3) b. Calculate the mass of the sole plate (3) c. The actual mass of the aluminium sole plate is less than the value

calculated in part b. using the technician’s data. Give one reason for this difference. (1)

washing

machine

Heating element

Water

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Q3. A steam cleaner rated at 2kW is used to clean a carpet. The water tank is filled with 1.6kg of water at 20°C. This water is heated until it boils and produces steam. The brush head is pushed across the surface of the carpet and steam is released.

Calculate how much heat energy is needed to bring this water to its boiling point of 100°C. (3)

Carpet Heating Element

Brush Head

Water tank

Mains Supply

Steam Pipe

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Q4. A steam wallpaper stripper is used on the walls of a room. Water is heated until it boils and produces steam. The plate is held against the wall and steam is released from the plate.

The tank is filled with water. The water has an initial temperature of 20°C.

a. Calculate the energy required to bring the water to its boiling point. (3) b. Calculate the time taken for this to happen. (3) c. The actual time taken for this to happen was found to be longer than

that calculated in b. Explain why. (1)

Power Rating 2.50kW Voltage 230V Mass of water 10kg

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Q5. A student carries out an experiment, using the apparatus shown, to determine a value for the specific heat capacity of water.

The student switches on the power supply and the immersion heater heats the water. The joulemeter measures the energy supplied to the immersion heater. The student records the following measurements.

energy supplied to immersion heater = 21,600 J mass of water = 0.50kg initial temperature of the water = 16°C

final temperature of the water = 24°C reading on voltmeter = 12V

reading on ammeter = 4.0A a. Determine the value of the specific heat capacity of water obtained from these measurements. (3) b. Explain why the value determined from the experiment is different from

the value quoted in the data sheet. (1)

Water Immersion

heater

Power supply Joulemeter

Beaker

Thermometer

A

V

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Q6. On the planet Mercury the surface temperature at night is –173°C. The surface temperature during the day is 307°C. A rock lying on the surface of the planet has a mass of 60.0kg.

The rock absorbs 2·59 × 107J of heat energy from the Sun during the day.

a. Calculate the specific heat capacity of the rock. (3) b. Heat is released at a steady 1440W at night. Calculate the time taken for the rock to release 2·59 × 107J of heat. (3) c. Energy from these rocks could be used to heat a base on the surface of

Mercury. How many 60kg rocks would be needed to supply a 288 kW heating system? (2)

d. Using information from the data sheet, would it be easier, the same or

more difficult to lift rocks on Mercury compared to Earth? You must explain your answer. 2

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Q7. A student carries out an experiment to measure the specific latent heat of vaporisation of water using the equipment shown below.

Describe how this apparatus would be used to determine a value for the specific latent heat of vaporisation of water. (3)

Your description must include:

• measurements made

• any necessary calculations

water immersion heater

power supply joulemeter

beaker

thermometer

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Gas Laws and the Kinetic Model Multiple Choice Questions Q1. A liquid is heated from 17°C to 50°C. The temperature rise in kelvin is

A 33 K B 67 K C 306 K D 340 K E 579 K.

Q2. A sealed canister contains gas at a pressure of 2·07 × 105 Pa. The

temperature of the gas is 10°C. The maximum safe pressure of the gas in the canister is 2·38 × 105Pa. The temperature of the gas at the maximum safe pressure is A 11°C B 49°C C 52 °C D 283°C E 325 °C.

Q3. The pressure of a gas in a sealed syringe is 1∙5 × 105 Pa. The temperature

of the gas is 27 °C. The temperature of the gas is now raised by 10 °C and the volume of the gas halved. The new pressure of the gas in the syringe is

A 1·1 × 105 Pa

B 2·8 × 105 Pa

C 3·1 × 105 Pa

D 4·1 × 105 Pa

E 11 × 105 Pa.

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Q4. An aircraft cruises at an altitude at which the external air pressure is 0·40 × 105Pa. The air pressure inside the aircraft cabin is maintained at 1·0 × 105Pa. The area of an external cabin door is 2·0 m2. What is the outward force on the door due to the pressure difference? A 0·30 × 105 N B 0·70 × 105 N C 1·2 × 105 N D 2·0 × 105 N E 2·8 × 105 N

Q5. A fixed mass of gas is heated inside a rigid container. As its temperature

changes from T1 to T2 and the pressure increases from 1·0 × 105Pa to 2·0 × 105Pa. Which row in the table shows possible values for T1 and T2?

Q6. One pascal is equivalent to

A 1 Nm B 1 Nm2

C 1 Nm3 D 1 Nm–2 E 1 Nm–3

T1 T2

A 27°C 327°C

B 30°C 60°C

C 80°C 40°C

D 303K 333K

E 600K 300K

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Q7. Which of the following increases the pressure of the gas? I Raising the temperature of the gas without changing its mass or

volume. II Increasing the mass of the gas without changing its volume or

temperature. III Increasing the volume of the gas without changing its mass or

temperature. A II only B III only C I and II only D II and III only E I, II and III

Q8. A solid at a temperature of -20°C is heated until it becomes a liquid at

70°C. The temperature change in kelvin is

A 50K B 90K C 343 K D 363 K E 596 K

Q9. A solid is heated from -15°C to 60°C. The temperature change of the solid

is A 45 K B 75 K C 258 K D 318 K E 348 K.

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Q10. The end of a bicycle pump is sealed with a stopper so that the air in the

chamber is trapped.

The plunger is now pushed in slowly causing the air in the chamber to be compressed. As a result of this the pressure of the trapped air increases. Assuming that the temperature remains constant, which of the following explain/s why the pressure increases? I The air molecules increase their average speed. II The air molecules are colliding more often with the walls of the

chamber. III Each air molecule is striking the walls of the chamber with greater

force. A II only B III only C I and II only D I and III only E I, II and III

Plunger

Chamber

Stopper

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Q11. The mass of a spacecraft is 1200 kg.

The spacecraft lands on the surface of a planet.

The gravitational field strength on the surface of the planet is 5.0 N kg-1. The spacecraft rests on three pads. The total area of the three pads is 1.5 m2. The pressure exerted by these pads on the surface of the planet is A 1.2 × 104Pa B 9.0 × 103Pa C 7.8 × 103Pa D 4.0 × 103Pa E 8.0 × 102Pa

Q12. A sealed bicycle pump contains 4.0 × 10−5m3 of air at a pressure of

1.2 × 105Pa. The piston of the pump is pushed in until the volume of air in the pump is reduced to 0.80 × 10−5m3. During this time the temperature of the air in the pump remains constant. The pressure of the air in the pump is now A 2.4× 104Pa B 1.2× 104Pa C 1.5× 104Pa D 4.4× 104Pa E 6.0× 104Pa.

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Gas Laws and the Kinetic Model Extended Response Questions Q1. Air is trapped in a syringe. The mass of the trapped air is 1·45 × 10−3 kg. The syringe of trapped air is set up with other apparatus as shown.

The trapped air is at a temperature of 20°C, a pressure of 1·01 × 105 Pa

and its volume is 5·00 × 10−4m3. The piston on the syringe is now pushed in until the volume of the trapped air is reduced to 1·25 × 10−4 m3. The temperature of the trapped air remains constant.

a. Calculate the pressure of the trapped air when its volume is 1·25 × 10−4m3. (3)

b. Use the kinetic model to explain what happens to the pressure of the trapped air as its volume is decreased. (2)

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Q2. A cylinder of compressed oxygen gas is in a laboratory. a. The oxygen inside the cylinder is at a pressure of

2.82×106Pa and a temperature of 19.0°C. The cylinder is now moved to a storage room where the temperature is 5.0°C. Calculate the pressure of the oxygen inside the cylinder when its temperature is 5.0°C. (3)

b. The valve on the cylinder is opened slightly so that oxygen is gradually

released. The temperature of the oxygen inside the cylinder remains constant. Explain, in terms of particles, why the pressure of the gas inside the cylinder decreases. (2)

c. After a period of time, the pressure of the oxygen inside the cylinder

reaches a constant value of 1.01 × 105Pa. The valve remains open. Explain why the pressure does not decrease below this value. (1)

Q3. A rigid cylinder contains 8.0 × 10-2 m3 of helium gas at a pressure of

750kPa. Gas is released from the cylinder to fill party balloons. During the filling process, the temperature remains constant. When filled, each balloon holds 0.020m3 of helium gas at a pressure of 125kPa.

a. Calculate the total volume of the helium gas when it is at a pressure of 125kPa. (3) b. Determine the maximum number of balloons which can be fully inflated

by releasing gas from the cylinder. (3)

Party Balloons

Rigid cylinder

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Q4. During the flight of an aircraft fuel is used. Explain why the pressure exerted by the tyres on the aircraft on the

runway after the flight is less than the pressure exerted by the tyres on the runway before the flight.

Q5. A student sets up an experiment to investigate the relationship between

the pressure and temperature of a fixed mass of gas as shown. a. The student heats the water and records the following readings of

pressure and temperature.

Pressure (kPa) 101 107 116 122

Temperature (K) 293 313 333 353

i. Using all the data, establish the relationship between the pressure and the temperature of the gas. (3) ii. Using the kinetic model, explain why the pressure of the gas increases as its temperature increases. (3) iii Predict the pressure reading which would be obtained if the student was to cool the gas to 253 K. (1) b. State one way in which the set-up of the experiment could be improved

to give more reliable results. (1)

Temperature sensor

Temperature meter

Water

Gas

Glass flask

Glass tube Pressure sensor

Heat