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Name: _______________________________________________
Solid,liquid & gases
Date:
Time: Total marks available: Total marks achieved: ______
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Questions
Q1.(a) A diver breathes air from a cylinder when he is under water.
(i) The cylinder contains 8 litres of air at 200 times atmospheric pressure.
The air is released from the cylinder at normal atmospheric pressure.
The diver needs 16 litres of air per minute.
Calculate the maximum amount of time that the diver can breathe under water using this cylinder.(3)
time = ........................................................... minutes
(ii) When the diver breathes out, bubbles are released.
Suggest why the bubbles expand as they rise to the surface.(2)
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(b) A student wants to investigate how the volume of a balloon changes with pressure.
(i) Suggest how the student could measure the volume of an inflated balloon. (2)
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(ii) The student plans to measure the pressure of the air in the balloon.
Explain why the student's plan will not work. (2)
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(Total for Question = 9 marks)
Q2.A student investigates ice, water and steam.
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She heats up a sample of ice.
When it has all melted, she carries on heating until the water has all boiled to steam.
(a) 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.(4)
(b) Complete the table by describing how the particles move in ice, water and steam. (3)
(Total for question = 7 marks)Q3.(a) The diagram shows the construction of a bicycle pump.
When the piston handle is pulled, air moves past the flexible rubber disc into space S.When the piston handle is pushed, the flexible rubber disc presses against the sides of the cylinder so no air can pass the disc in either direction.
(i) When the volume of space S is 80 cm3, the air in space S has a pressure of 1.01×105 Pa.
The valve is sealed so no air can escape from the pump.
Calculate the pressure inside space S when the piston handle is pushed in and the volume decreases to 10 cm3. (3)
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pressure = ........................................................... Pa
(ii) State an assumption you have made about the air in space S.(1)
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(iii) When the bicycle pump is used to inflate a tyre, the pump becomes hot.Suggest why the pump becomes hot.
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(b) The photograph shows a woman using a pump to lift water from a well.
(i) State the relationship between work done, force and distance moved.(1)
(ii) Calculate the work done in lifting 1.25 kg of water a distance of 8.70 m.(3)
work done = ........................................................... J
(Total for question = 10 marks) Q4.All gases above absolute zero exert a pressure on the walls of their container.
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(a) (i) State the value of absolute zero in °C.
(1)
absolute zero = .........................................°C(ii) Explain, in terms of its molecules, how a gas exerts a pressure on the walls of its container.
(3).............................................................................................................................................................
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............................................................................................................................................................(b)A pressure switch is used in a washing machine to control the flow of water. The water pushes on a flexible container and compresses some trapped air.When the pressure of this trapped air reaches 104kPa, the pressure switch turns the water off.
The pressure of the trapped air is given by this relationship
(i) State the equation linking pressure difference, height, density and g.(1)
(ii) Calculate the height of water in the machine when the pressure of the trapped air reaches 104 kPa and the switch operates.[atmospheric pressure = 100 kPa, density of water = 1000 kg/m3]
(4)
height of water = ...............................................m
(Total for question = 9 marks) Q5.The diagram shows a can that produces whipped cream using gas at high pressure.
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The volume of the high pressure gas container is 10 cm3.
The pressure of the gas is 10 000 kPa.
When the seal at S is broken, the gas is released into the space above the cream.
The gas expands to a total volume of 270 cm3.
(a) Calculate the new pressure of the gas.(2)
Pressure = ........................................................... kPa
(b) As the gas expands into the space above the cream, its temperature decreases.Using ideas about molecules, explain how this affects the pressure of the gas.
(3) ................................................................................................................................................................
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............................................................................................................................................................(c) Some of the gas molecules dissolve into the cream.
(i) Suggest how this affects the pressure of the gas in the space above the cream.(2)
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...........................................................................................................................................................(ii) When the tap is opened, the pressure of the gas forces the cream out of the spout.The pressure outside the can is less than it is inside.Suggest what happens to the dissolved gas as the cream leaves the can.
(1) ................................................................................................................................................................
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Q6.A cooling tower is designed to transfer thermal energy away from a power station.
a)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.
Explain why the air moves as shown by the arrows.(4)
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(b) 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.
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Explain how evaporation cools the water.(3)
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(Total for question = 7 marks) Q7.A student uses a pressure sensor to measure the pressure of air in a sealed flask.
(a) The pressure sensor measures pressure in pascals (Pa).
Which of these is equivalent to pascals (Pa)?(1)
A joules per metre (J/m)
B joules per square metre (J/m2)
C newtons per metre (N/m)
D newtons per square metre (N/m2)
(b) The student places the flask in a beaker containing hot water.
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The pressure of the air in the flask increases.Explain why the pressure of the air in the flask increases.Use ideas about molecules in your answer.
(3) ................................................................................................................................................................
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(Total for question = 4 marks) Q8.The picture shows a runner.
(a) 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.
(3) ................................................................................................................................................................
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.............................................................................................................................................................. (b) At the end of a long race, runners are given a shiny foil sheet to wear.
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This stops them cooling down too quickly.
(i) Suggest why a runner might cool down too quickly if he does not wear a foil sheet.(2)
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...........................................................................................................................................................(ii) Explain how the foil sheet reduces heat loss.
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............................................................................................................................................................ (Total for question = 7 marks)Q9.A student uses this apparatus to investigate the pressure and volume inside a sealed gas syringe.
She takes readings of the volume as she increases the pressure (loading) and as she decreases the pressure (unloading).
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These are her results.
(a) (i) Complete the table by filling in the missing value.
(1)(ii) Suggest why the student takes readings for increasing the pressure and for decreasing the pressure.
(2) .............................................................................................................................................
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(b) The student plots this graph.
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(i) Suggest a reason why the axes do not start from the origin (0,0).(1)
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(ii) The student has drawn both a straight line of best fit and a curve of best fit.Discuss which line is correct for this investigation.
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(iii) Suggest a way that the student could make this experiment valid (a fair test).(1)
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(iv)Suggest two ways in which the student could improve the quality of her data.
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(c) The student concludes that her data validates the relationship between pressure and volume of a fixed mass of gas.
Use data from this table to evaluate her conclusion.(3)
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(Total for question = 12 marks) Q10.The photograph shows a car tyre that needs to be inflated.
The tyre exerts a pressure on the road of 270 kPa.
The area of the tyre touching the road is 0.016 m2.
(a) (i) State the equation linking pressure, force and area.
(1)
(ii)Calculate the force exerted on the road by the tyre.Give the unit.
(4)
force = ............................. unit .............................
(b) Use ideas about molecules to explain why the air inside the tyre exerts pressure.
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(c) Air is pumped into the tyre to inflate it.
This increases the temperature and the pressure of the air in the tyre.Use ideas about molecules to explain why the air pressure in the tyre increases. (3)
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(Total for question = 11 marks)Q11.Aneroid barometers are used to measure air pressure.
A student makes a model aneroid barometer as shown.
(a) (i) The balloon fabric is attached to the can to stop the air escaping.
Explain how the air inside the can causes a pressure on the balloon fabric.(3)
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(ii) The balloon fabric is tight and flat.The pointer is horizontal as shown.
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Explain what happens to the different parts of the model when the atmospheric pressure increases. [You may assume that the temperature remains constant.]
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(iii) Suggest two ways that the model could be altered to increase its sensitivity to changes in atmospheric pressure. (2)1 ............................................................................................................................................................
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(b) The student heats the air in her can by placing the can in a water bath.
(i) State how this affects the reading shown by the pointer.(1)
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(ii) Explain why this happens.(2)
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(Total for question = 12 marks) Q12.Liquid helium boils at 4.2 K.
(a) Convert 4.2 K to a temperature in °C.
(1)
temperature = ...........................................................°CPage | 16
(b) Liquid helium boils to form helium gas.
(i) State two ways in which the arrangement and motion of the molecules change as the helium becomes a gas.
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(ii) The average kinetic energy of the molecules in helium gas depends on its Kelvin temperature.
Sketch a graph on the axes below to show this relationship. (2)
(c) Some air is trapped in a narrow glass tube so that its pressure remains constant.
Describe how this apparatus can be used to investigate the relationship between the temperature and the volume of air at constant pressure.
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You may add to the diagram to help your answer.(4)
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(Total for question = 9 marks)Q13.The diagram shows some gas particles in a container.
The piston can be moved in or out to change the volume of the gas.
(a) Add arrows to the diagram to show the random motion of the gas particles.
(2)(b) Explain how the motion of the gas particles produces a pressure inside the container.
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......................................................................................................................................................... (c) State what would happen to the pressure if you pushed the piston into the container without changing the temperature.
(1) .............................................................................................................................................
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(d) When the gas in the container is heated, the piston moves outwards.
Place ticks against the three correct statements. (3)
(Total for question = 9 marks) Q14.The particles in the different states of matter behave differently.
(a) Draw a straight line linking each state of matter with the description of its particles. (2)
(b) 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)
(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).................................................................................................................................................................
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(iii) State what happens to the volume of an ethyne molecule when the gas changes to a solid at the triple point.
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(Total for question = 6 marks) Q15.A hot air balloon is filled with air through an opening.The air is heated using a burner.
(a) Describe the effect of an increase in temperature on the average speed of the air molecules.
(1)...........................................................................................................................................................
(b) The hot air causes a pressure on the inside of the balloon.
Use ideas about molecules to explain how the hot air causes this pressure.(3)
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(c) Give a reason why the hottest air rises to the top of the balloon.
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(d) The average density of the hot air in the balloon is 0.95 kg/m3.The volume of this air is 2800 m3.
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(i) State the equation linking density, mass and volume.(1)
(ii) Calculate the mass of hot air in the balloon.(3)
mass of hot air = .......................................... kg
(e)As the balloon climbs higher, the air pressure outside it decreases.
(i) Suggest a reason for this change in the outside air pressure.(1)
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(ii) Suggest how the decrease in air pressure outside the balloon affects the hot air inside.(1)
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(Total for question = 11 marks)
Q16.(a)The diagram shows the fuel used in some nuclear reactors.The fuel is contained inside spheres.The silicon carbide layer of each sphere is designed to contain the fission products for at least one million years.
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(i) Give the name of a fuel that could be used.(1)
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(ii) Explain what is meant by the term fission products.(2)
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(iii) Explain why it is important to contain these fission products for such a long time.(2)
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(iv) The graphite layer in every fuel sphere acts as a moderator.What is the function of the moderator in a nuclear reactor?
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(v) The nuclear reactor also contains boron control rods.Explain why it is dangerous to remove most of the control rods from the reactor.
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........................................................................................................................................................... (b) The reactor is cooled with helium gas.
The gas enters the reactor at 500 °C.(i) What is this temperature in kelvin?
(1) temperature = ........................................................... K
(ii) Helium gas enters the reactor at a pressure of 8.40 MPa and leaves the reactor at a temperature of 1170 K.
Calculate the pressure of the helium gas as it leaves the reactor.[assume the volume of the gas does not change]
(3)
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pressure = ........................................................... MPa
(Total for question = 12 marks) Q17.A student blows up two balloons to the same size.
She puts one balloon into a freezer.
After a while, the student compares the two balloons. The balloon that has been cooled is smaller.
(a) Use ideas about particles to explain why the cooled balloon is smaller.(4)
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(b)The student decides to investigate the link between temperature and the size of the balloon.
She writes a plan.
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There are several faults in the student's plan.Identify three of these faults and suggest an improvement to correct each one.
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(Total for question = 10 marks)Q18.Compressed air from a can is used to clean computer keyboards.
(a) Use ideas about particles to explain how a gas causes a pressure on the inside of a container.(3)
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(b) The can has a warning sign on it.
(i) How would increasing the temperature of the compressed air affect the pressure in the can?(1)
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(ii) Explain your answer.(2)
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(c) The can has a volume of 400 cm3 and the pressure of the compressed air inside is 5 times atmospheric pressure.
Calculate the volume that the air would occupy if it were all released to atmosphericpressure.
(2)
Volume = ........................................................... cm3
(Total for question = 8 marks)Page | 25
Q19.A spray-can contains gas particles that are constantly moving.
(a) (i) How do the gas particles produce a pressure on the walls of the spray-can?(3)
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.......................................................................................................................................................(ii) A student presses the button and some liquid leaves the can.The student concludes
Evaluate this conclusion.(3)
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........................................................................................................................................................(b) What happens to the average speed of the gas particles when the spray-can is warmed by the sun on a hot day?
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.......................................................................................................................................................... (Total for question = 7 marks)Q20.A diver works in the sea on a day when the atmospheric pressure is 101 kPa and the density of the seawater is 1028 kg/m3.
(a) The diver uses compressed air to breathe under water.
1700 litres of air from the atmosphere is compressed into a 12-litre gas cylinder.
The compressed air quickly cools to its original temperature.
Calculate the pressure of the air in the cylinder.(3)
pressure = ........................................................... kPa
(b)(i)State the equation linking pressure difference, depth, density and g.
(1)
(ii)Calculate the increase in pressure when the diver descends from the surface to a depth of 11 m.(2)
increase in pressure = ......................................... kPa
(iii) Calculate the total pressure on the diver at a depth of 11 m.Assume that the atmospheric pressure remains at 101 kPa.
(1)
total pressure = ........................................................... kPa
(c) As the diver breathes out, bubbles of gas are released and rise to the surface.
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The bubbles increase in volume as they rise.Explain this increase in volume.
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(Total for question = 9 marks) Q21.James Dewar was a scientist who investigated liquid oxygen.
(a) He discovered that the boiling point of liquid oxygen is −183 °C.(i) Convert −183 °C to a temperature on the Kelvin scale.
(1)
Temperature = ........................................................... K
(ii) Use ideas about particles to describe the changes that happen when a liquid boils to form a gas.(3)
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.......................................................................................................................................................(b) Dewar invented a special flask for storing liquid oxygen in the laboratory.
It was designed to reduce heat flow from the air outside to the liquid oxygen inside.The flask had two glass walls with a vacuum between them.The inside glass surfaces were each covered with a thin layer of shiny metal.The diagram shows a cross section of the flask.
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(i) Explain how the shiny surfaces reduce the thermal energy transferred to the liquid oxygen from the laboratory.
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(ii) Explain how the vacuum reduces the thermal energy transferred to the liquid oxygen from the laboratory.
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(c) Dewar's flask did not have a lid when it was holding liquid oxygen.Suggest why a lid was not needed.
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Q22.(a) Temperature can be measured using different scales.Complete the table by inserting the missing temperatures. (2)
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(b) Some students measure the volume of a sample of gas at different temperatures.The table below shows their results.
(i) Draw a graph to show how the volume of gas varies with temperature. (3)
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(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
(Total for question = 7 marks)
Q23.The photograph shows a kettle on a camping stove. The cylinder contains some gas.
(a) Water in the kettle boils at a temperature of 100 °C and steam is produced.(i) Convert this to a temperature on the Kelvin scale.
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(1)
100 °C = ........................................................... K(ii) State one way in which the molecules in steam are different from the molecules in water.
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...............................................................................................................................................................(iii) Explain how the molecules of steam exert a pressure on the inside of the kettle.
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................................................................................................................................................................(b)The wind blows the flame out and 820 cm3 of gas, at a pressure of 130 kPa, escapes from the cylinder.As the gas escapes, its pressure decreases to 101 kPa.Calculate the volume of the escaped gas at a pressure of 101 kPa.
(2)
Volume = ........................................................... cm3
(c) The cylinder is turned off to stop more gas escaping.The temperature of the gas in the cylinder decreases.Explain what happens to the pressure of the gas in the cylinder.
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............................................................................................................................................................... (Total for question = 9 marks)Q24.The properties of materials can be explained using particle theory.
These are some observations about samples of ice, water and steam.
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Explain each of the observations in terms of the arrangement and motion of the particles. You may use diagrams to help your answer.
(6)
particles in ice......................................................................................................................................
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particles in water...............................................................................................................................
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(Total for Question = 9 marks)
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