P1 02 Kinetic Theory

74minutes

74marks

Q1. The drawing shows water being heated in a metal saucepan.

(a) Explain, in terms of the particles in the metal, how heat energy is transferred through the base of the saucepan.

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(2)

(b) Energy is transferred through the water by convection currents. Explain what happens to cause a convection current in the water. The answer has been started for you.

As heat energy is transferred through the saucepan, the water particles at the bottom

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(3)

(c) Some energy is transferred from the hotplate to the air bythermal radiation. What is meant bythermal radiation?

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(1)

(Total 6 marks)

Q2.(a) The graph shows how the temperature of a pure substance changes as it cools from 330C.

Explain why the temperature of the substance is constant between the points markedJandK.

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(2)

(b) A book of scientific data contains the statement:

The specific latent heat of fusion of pure ice is 3.3 105J/kg.

What does this statement mean?

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(1)

(c) The diagram shows one method of measuring the specific latent heat of fusion of ice in a laboratory where the temperature is 20 C. Two funnels,AandB, contain equal amounts of crushed ice at 0 C.

The mass of melted ice from each funnel is measured after 12 minutes.

The joulemeter measures the energy supplied to the heater.

(i) Why is it necessary to set up funnelBto obtain an accurate result?

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(2)

(ii)The measurements taken are given in the table.

Mass of melted ice collected from funnelA

63 g

Mass of melted ice collected from funnelB

24 g

Joulemeter reading

17160

Use the data in the table to calculate the specific latent heat of fusion of ice.

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Specific latent heat of fusion of ice = ......................................... J/kg

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(iii)Suggestonereason why the value obtained by this method and the value given in the data book are not the same.

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(1)

(Total 8 marks)

Q3. (a) The diagram shows a tray of marbles being shaken from side to side. As this happens some of the marbles jump out of the tray.

Explain how the tray of marbles is acting as a model for the evaporation of a liquid.

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(2)

(b) Before giving an injection, a nurse dabs some alcohol onto the patients arm. This makes the patients skin feel cold.

Explain what happens to make the patients skin feel cold.

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(2)

(c) The graph shows that the molecules in a liquid do not all have the same speed.

Use the information in the graph to explain why a liquid cools down when it evaporates.

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(5)

(Total 9 marks)

Q4. Marbles inside a box can be used as a model for the particles in a solid, a liquid or a gas.

Use words from the box to complete the following sentences. Each word can be used once, more than once or not at all.

gas liquid solid

(a) The particles in a............................................vibrate about fixed positions.

(1)

(b) The particles in a..........................................move at high speed in any direction.

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(c) The particles in a............................................are arranged in a pattern.

(1)

(Total 3 marks)

Q5.(a)The diagrams show the arrangement of the particles in a solid and in a gas.

Each circle represents one particle.

(i) Complete the diagram below to show the arrangement of the particles in a liquid.

(2)

(ii)Explain, in terms of the particles, why gases are easy to compress.

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