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Drayton Manor High School

P6 Old Exam Questions

Q1. The figure below shows a balloon filled with helium gas.

(a) Describe the movement of the particles of helium gas inside the balloon.

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(b) What name is given to the total kinetic energy and potential energy of all the particles of helium gas in the balloon?

Tick one box.

External energy

Internal energy

Movement energy

(1)

(c) Write down the equation which links density, mass and volume.

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(d) The helium in the balloon has a mass of 0.00254 kg.

The balloon has a volume of 0.0141 m3.

Calculate the density of helium. Choose the correct unit from the box.

m3 / kg kg / m3 kg m3

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Density = .................................... Unit .................. (3)

(Total 7 marks)

Q2. A student investigated the cooling effect of evaporation.

She used the equipment (datalogger and probe) shown in Figure 1 to measure how the temperature of a liquid changed as the liquid evaporated.

Figure 1

(a) Which type of variable was the temperature in this investigation?

Tick (✔) one box.

Tick (✔)

control

dependent

independent

(1)

(b) Before the investigation started, the student checked the accuracy of three different temperature probes. The student put the probes in a beaker of boiling water that had a temperature of 100.0 °C. The readings from the three temperature probes are shown in Figure 2.

Figure 2


Which one of the temperature probes, A, B or C, was least accurate?

Write the correct answer in the box.

Give a reason for your answer.

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(c) Figure 3 shows how the temperature recorded changed during the investigation.

Figure 3

(i) Use Figure 3 to determine the lowest temperature recorded as the liquid evaporated.

Temperature = ............ °C (1)

(ii) Use Figure 3 to determine how long it took for all the liquid to evaporate. Give a reason for your answer.

Time = ............... seconds

Reason: ....................................................................................................

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(iii) How would increasing the starting temperature of the liquid above 20 °C affect the rate of evaporation of the liquid?

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(Total 7 marks)

Q3. Two students investigated the change of state of stearic acid from liquid to solid.

They measured how the temperature of stearic acid changed over 5 minutes as it changed from liquid to solid.

Figure 1 shows the different apparatus the two students used.

Figure 1

Student A’s apparatus Student B’s apparatus

(a) Choose two advantages of using student A’s apparatus.

Tick two boxes.

Student A’s apparatus made sure the test was fair.

Student B’s apparatus only measured categoric variables.

Student A’s measurements had a higher resolution.

Student B was more likely to misread the temperature.

(2)

(b) Student B removed the thermometer from the liquid each time he took a temperature reading.

What type of error would this cause?

Tick one box.

A systematic error


A random error

A zero error

(1)

(c) Student A’s results are shown in Figure 2.

Figure 2

What was the decrease in temperature between 0 and 160 seconds?

Tick one box.

8.2 °C

8.4 °C


53.2 °C

55.6 °C

(1)

(d) Use Figure 2 to determine the time taken for the stearic acid to change from a liquid to a solid.

Time = ........................ seconds (1)

(e) Calculate the energy transferred to the surroundings as 0.40 kg of stearic acid changed state from liquid to solid.

The specific latent heat of fusion of stearic acid is 199 000 J / kg.

Use the correct equation from the Physics Equations Sheet.

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Energy = ......................................... J (2)

(f) After 1200 seconds the temperature of the stearic acid continued to decrease.

Explain why.

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(Total 9 marks)

Q4. In this question you will be assessed on using good English, organising information clearly and using specialist terms where appropriate.

The information in the box is about the properties of solids and gases.

Solids: • have a fixed shape • are difficult to compress (to squash). Gases: • will spread and fill the entire container • are easy to compress (to squash).


Use your knowledge of kinetic theory to explain the information given in the box.

You should consider: • the spacing between the particles • the movement of individual particles • the forces between the particles.

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Extra space .............................................................................................................

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Q5. (a) The diagrams, X, Y and Z, show how the particles are arranged in the three states of matter.

(i) Which one of the diagrams, X, Y or Z, shows the arrangement of particles in a liquid?

Write the correct answer in the box. (1)

(ii) Which one of the diagrams, X, Y or Z, shows the arrangement of particles in a gas?

Write the correct answer in the box. (1)

(b) Draw a ring around the correct answer in each box to complete each sentence.

vibrating in fixed positions.

(i) In a gas, the particles are moving randomly.

not moving.

(1)

stronger than

(ii) In a solid, the forces between the particles are equal to the forces between

weaker than

the particles in a liquid. (1)


(c) The picture shows a puddle of water in a road, after a rain shower.

(i) During the day, the puddle of water dries up and disappears. This happens because the water particles move from the puddle into the air.

What process causes water particles to move from the puddle into the air?

Draw a ring around the correct answer.

condensation evaporation radiation

(1)

(ii) Describe one change in the weather which would cause the puddle of water to dry up faster.

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(Total 6 marks)

Q6. A new design for a kettle is made from two layers of plastic separated by a vacuum. After the water in the kettle has boiled, the water stays hot for at least 2 hours.

The new kettle is shown below.

(a) The energy transferred from the water in the kettle to the surroundings in 2 hours is


46 200 J.

The mass of water in the kettle is 0.50 kg.

The specific heat capacity of water is 4200 J/kg °C.

The initial temperature of the water is 100 °C.

Calculate the temperature of the water in the kettle after 2 hours.

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Temperature after 2 hours = ...................... °C (3)

(b) Calculate the average power output from the water in the kettle to the surroundings in 2 hours.

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Average power output = ........................... W (2)

(Total 5 marks)

Q7. The picture shows a person taking a hot shower.

(a) When a person uses the shower the mirror gets misty.

Why?

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(b) The homeowner installs an electrically heated mirror into the shower room.

When a person has a shower, the heated mirror does not become misty but stays clear.

Why does the mirror stay clear?

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(Total 5 marks)

Q8. The diagram shows two thermometers. The bulb of each thermometer is covered with a piece of wet cotton wool. One of the thermometers is placed in the draught from a fan.


The graph shows how the temperature of each thermometer changes with time.

(a) Which of the graph lines, A or B, shows the temperature of the thermometer placed in the draught?

Write the correct answer in the box.

Explain, in terms of evaporation, the reason for your answer.

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(b) A wet towel spread out and hung outside on a day without wind dries faster than an identical wet towel left rolled up in a plastic bag.

Explain why.

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(Total 5 marks)


ANSWERS

M1.(a) range of speeds 1

moving in different directions

accept random motion 1

(b) internal energy 1

(c) density = mass / volume 1

(d) 0.00254 / 0.0141 1

0.18 1

accept 0.18 with no working shown for the 2 calculation marks

kg / m3

1 [7]

M2.(a) dependent 1

(b) (probe) C

allow 103.2 1

largest difference between reading and actual temperature

reason only scores if C chosen

accept larger

it is 3.2 greater is insufficient


comparing C with only one other probe is insufficient 1

(c) (i) 12(°C)

accept a value between 12.0 and 12.2 inclusive 1

(ii) 140 (seconds)

accept an answer between 130 and 150 inclusive 1

temperature starts to rise

only scores if time mark awarded

accept the temperature was lowest (at this time) 1

(iii) increase

accept faster (rate) 1

[7]

M3.(a) Student A’s measurements had a higher resolution 1

Student B was more likely to misread the temperature 1

(b) a random error 1

(c) 8.4 °C 1

(d) 740 (seconds)

allow answers in the range 730 – 780 1

(e) 0.40 × 199 000 1

79 600 (J)


1

accept 79 600 (J) with no working shown for 2 marks

(f) stearic acid has a higher temperature than the surroundings

accept stearic acid is hotter than the surroundings 1

temperature will decrease until stearic acid is the same as the room temperature / surroundings

1 [9]

M4.Marks awarded for this answer will be determined by the Quality of Written Communication (QWC) as well as the standard of the scientific response. Examiners should also apply a ‘best-fit’ approach to the marking.

0 marks No relevant content.

Level 1 (1–2 marks) Considers either solid or gas and describes at least one aspect of the particles.

or

Considers both solids and gases and describes an aspect of each.

Level 2 (3–4 marks) Considers both solids and gases and describes aspects of the particles.

or

Considers one state and describes aspects of the particles and explains at least one of the properties.

or

Considers both states and describes an aspect of the particles for both and explains a property for solids or gases.

Level 3 (5–6 marks) Considers both states of matter and describes the spacing and movement / forces between the particles. Explains a property of both solids and gases.

examples of the points made in the response

extra information

Solids


• (particles) close together • (so) no room for particles to move closer (so hard to compress) • vibrate about fixed point • strong forces of attraction (at a distance) • the forces become repulsive if the particles get closer • particles strongly held together / not free to move around (shape is fixed)

any explanation of a property must match with the given aspect(s) of the particles.

Gases

• (particles) far apart • space between particles (so easy to compress) • move randomly • negligible / no forces of attraction • spread out in all directions (to fill the container)

[6]

M5.(a) (i) Z 1

(ii) X 1

(b) (i) moving randomly 1

(ii) stronger than 1

(c) (i) evaporation 1

(ii) any one from:

• becomes windy

• temperature increases

accept (becomes) sunny“the sun” alone is insufficient

• less humid


1 [6]

M6.(a) 78 (°C)

allow 2 marks for correct temperature change ie 22 °C

allow 1 mark for correct substitution

ie 46 200 = 0.5 × 4200 x θ

or

3

(b) 6.4 (W)

allow 2 marks for an answer that rounds to 6.4

allow 1 mark for correct substitution

ie 46 200 = P × 7200

an answer of 23 000 or 23 100 or 385 gains 1 mark 2

[5]

M7.(a) any two from:

• water evaporates

accept steam / water vapour for water molecules

accept water turns to steam

• water molecules / particles go into the air

• mirror (surface) is cooler than (damp) air

accept the mirror / surface / glass is cold

• water molecules / particles that hit the mirror lose energy

accept water molecules / particles that hit the mirror cool down

• cooler air cannot hold as many water molecules / particles 2

(causes) condensation (on the mirror)

accept steam changes back to water (on the mirror)

orparticles move closer together 1


(b) mirror (surface) is warm

mirror is heated is insufficient 1

(rate of) condensation reduced

accept no condensation (happens) 1

[5]

M8. (a) B

no mark for B - marks are for the explanation

first two mark points can score even if A is chosen

draught increases (the rate of) evaporation

accept more evaporation happens

accept draught removes (evaporated) particles faster

do not accept answers in terms of particles gaining energy from the fan / draught

1

evaporation has a cooling effect

accept (average) kinetic energy of (remaining) particles decreases

1

so temperature will fall faster / further 1

(b) larger surface area 1

increasing the (rate of) evaporation

accept more / faster evaporation

accept easier for particles to evaporate

or

for water to evaporate from

accept more particles can evaporate


accept water / particles which have evaporated are trapped (in the bag)

answers in terms of exposure to the Sun are insufficient 1

[5]


EXAMINER’S NOTES ON SELECTED QUESTIONS

E2.(a) Just over a third of students scored this mark. The most common incorrect answer was control.

(b) Almost three quarters of students scored the mark for choosing probe C, a lot of students found it difficult to articulate their ideas to explain their choice. A common incorrect answer was that C was an anomaly, or was inaccurate because it was above 100⁰C and the temperature should have been going down, not up. Just over a third of students scored both marks.

(c) (i) Just over half of students scored this mark. Some students incorrectly read the scale and were outside the tolerance; others misunderstood the graph and stated 20 °C or 13.5 °C.

(ii) A quarter of students scored only 1 mark by stating the correct time, but a fifth of students scored both marks.

(iii) Half of students scored this mark, most incorrect responses stated the opposite effect, that rate of evaporation would be lower.

E4.A low proportion of students were able to make a relevant comment on the arrangements of particles in solids or gases.

Generally, most students made a good attempt at the question, with few students leaving it blank. Most were able to make sensible statements about the spacing and movement of particles in solids and gases, but rather fewer referred to the forces between the particles: fewer still attempted to use these statements to explain the properties given in the information box.

Too many students simply repeated the information given in the question and weaker students wrote all they knew, including about particles and their behaviour in a liquid The use of the term ‘kinetic theory’ in the question distracted some students into describing conduction and convection. Others became obsessed with the fact that free electrons make metals good conductors.

More able students could select the relevant property of particles to explain the macroscopic property of solids and gases.

E5.(a) (i) Nearly all students answered this correctly.

(ii) Nearly all students answered this correctly.

(b) (i) Nearly all students answered this correctly.

(ii) Nearly all students answered this correctly.

(c) (i) The majority of students correcty chose evaporation.

(ii) Most students knew that if the weather became warmer or more windy the puddle of water would evaporate faster. A few students were unspecific and simply wrote “temperature” or “the Sun”.


E6.(a) This question discriminated well, a third of students scored all 3 marks. A third of students scored 2 marks for calculating the temperature change of 22°C. Surprisingly, many students thought the final temperature would be 122°C having added the 22°C to the initial temperature. These students still scored 2 marks for their calculation of temperature change provided working was shown. A surprising number of students failed to correctly subtract 22 from 100, believing the answer to be 88°C.

A number of students selected an incorrect equation. Some students scored 1 mark for the substitution only and then incorrectly rearranged to achieve an incorrect final answer. Students should be reminded that the substitution gains 1 mark, not the subsequent rearrangement

(b) Only one tenth of students scored 2 marks for the answer of 6.4 (W). Half the students scored 1 mark, with the most commonly seen answer of 23 100, which was achieved by dividing 46 200 by 2 (hours). A number of students attempted the conversion, but only got as far as minutes and ended with an answer of 385, which also scored 1 mark.

E7.(a) This question discriminated well, with the best students scoring all three marks. However, there was much confusion about terminology with the terms condensation, convection and evaporation apparently interchangeable in many answers. The most common way of gaining a mark was to say that condensation was occurring. The verb “to condensate” was almost universal.

(b) Most students realised that condensation would not take place, although condensation followed by evaporation from the mirror surface was common. Many thought that warm air was “attracted” to a cold surface. Others did not state that the mirror was warm and simply repeated the “heated mirror” from the stem of the question. As in part (a) the meaning of “evaporation” and “condensation” was not clear.

E8. (a) Very few students showed an understanding of evaporation. Many students thought that the fan must be blowing hot air onto the thermometer, and therefore chose thermometer A. Others chose thermometer B but thought that this was because the air from the fan was colder than the surrounding air.

(b) This part was also badly answered. Many students thought that ‘the Sun would not get through the plastic Many’. bag others failed to notice that the towel was hung outside on a day without wind, and were stating that the towel in the bag would remain wet because there was no wind.

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