States of Matter & Thermal Capacity (Edexcel GCSE Physics)

Describe, in terms of particles, two differences between a solid and a liquid of the same substance.

Figure 6 shows the dimensions of a solid block of concrete.

Figure 6

Density of concrete, ρ, = 2100 kg/m³.

Calculate the mass of the concrete block.

Use the equation

m = ρ × V

mass of concrete block = ................................ kg

Figure 7 shows a shed made mostly of concrete blocks.

Figure 7

State two practical ways to reduce heat loss from this shed.

1 ...............................................................................................

2 ...............................................................................................

On a very cold day, the temperature of the air is −4°C.

Calculate the value of this temperature on the kelvin scale.

temperature = .............................................................. K

A student measures the density of glass.

The student has

− a bag of marbles, all made from the same type of glass

− a weighing balance

− a plastic measuring cylinder containing water

Describe how the student could find, as accurately as possible, the density of the glass used for the marbles.

A beaker contains 0.25kg of water at room temperature.

The beaker of water is heated until the water reaches boiling point (100°C).

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

The total amount of thermal energy supplied to the water is 84 000J.

(i) Calculate the temperature of the water before it was heated. Use an equation selected from the list of equations at the end of this paper.

      temperature before heating = .......................... °C [3]

(ii) The heating continues until 0.15 kg of the water has turned into steam. The thermal energy needed to turn the boiling water into steam is 0.34 MJ.

Calculate the specific latent heat of vapourisation of water.

Use an equation selected from the list of equations at the end of this paper.

        specific latent heat = ................................... MJ/kg [2]

(iii) The graph in Figure 13 shows how the volume of 1kg of water changes with temperature. 

Figure 13

Describe how the density of water changes with temperature over the range of temperature shown in Figure 13.

Calculations are not required.

[2]

Solid, liquid and gas are states of matter.

Which process describes the change from a solid to a liquid?

A student determines the density of a liquid.

The student puts an empty measuring cylinder on a balance (Figure 10a).

The student then adds liquid to the measuring cylinder (Figure 10b).

Calculate the mass of liquid added and the volume of liquid added.

Use the information in Figures 10a and 10b.

Determine 

i) mass of liquid added = ............................................... g

[1]

ii) volume of liquid added = ............................................... cm³

[1]

iii) Which equation should the student use to calculate the density of the liquid?

[1]

iv) State two improvements the student could make to this investigation.

[2]

i) Figure 11 shows an electric kettle.

Figure 11

The kettle contains 1.5kg of water.

The kettle is switched on.

Calculate the energy needed to raise the temperature of the water by 50 °C.

Specific heat capacity of water = 4200 J/kg°C

Use the equation

energy needed = ............................................... J[2]

ii) The amount of energy, E, needed to bring the water to boiling point is 670 000 J.

The kettle has a power of 3500 W.

Calculate the time, t, it takes to bring the water to boiling point.

Use the equation

time to bring the water to boiling point = ....................... s[3]

Water vapour is contained in a lidded beaker.

Describe the movement of the particles in:

(i) The solid box

[1]

(ii) The water vapour

[2]

As the water vapour cools, the temperature is taken at regular intervals.

Sketch a graph to show the change in temperature with time.

Explain what is meant by the specific heat capacity of a substance.

A mass of 170 g of water is needed to make a cup of coffee which is brewed at an optimum temperature of 80 ºC. The water is heated in a kettle from a temperature of 55 ºC from the tap.

The specific heat capacity of water = 4200 J kg¹ K¹.

Calculate the energy needed to boil the water.

A student uses the apparatus in Figure 3 to determine the specific heat capacity of water.

Figure 3

(i) State the measurements needed to calculate the specific heat capacity of water.

[4]

(ii) State two ways that the apparatus could be adapted to improve the procedure.

[2]

The student decides to measure the temperature of the water every minute while it is being heated.

Figure 4 shows a graph of the student’s results.

Figure 4

Predict the temperature of the water if the heating continues up to 8 minutes.

temperature of the water = ............................................... °C

Another student decides to melt some ice.

The student melts 380g of ice at 0°C.

The specific latent heat of fusion of ice is 3.34 × 10⁵ J/kg.

Calculate the thermal energy needed to melt the ice.

Select an equation from the list of equations at the end of this paper

thermal energy needed = ............................................. J

An electric kettle contains 1.41 kg of water at 25°C.

The kettle is switched on.

After a while, the water reaches boiling point at 100°C.

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

(i) Calculate the amount of thermal energy supplied to the water by the kettle.

Give your answer to the appropriate number of significant figures.

Use an equation selected from the list of equations at the end of the paper.

energy supplied = .............................................................. J[3]

(ii) The kettle is kept switched on and the water continues to boil.

After a while, the mass of the water in the kettle has decreased to 1.21 kg.

The thermal energy supplied to the water during this time was 450000 J.

Calculate the specific latent heat of vaporisation of water.

Use an equation selected from the list of equations at the end of the paper.

specific latent heat of vaporisation = ......................... J/ kg[3]

This question is about determining the specific heat capacity of aluminium.

An aluminium block is placed in boiling water as shown in Figure 21.

Figure 21

The piece of string is tied to the aluminium block so the block can be transferred from the boiling water to the cold water.

Describe how a student could use this apparatus, and any additional items needed, to determine the specific heat capacity of aluminium.

Your answer should include how the student would

• obtain the necessary measurements

• use the measurements to calculate the specific heat capacity of aluminium.

A student investigates the density of a brick and the density of a small toy, as shown in Figure 1.

Figure 1

The student found the volume of the brick by multiplying the area of its base by its height. The fish toy does not have straight sides.

Describe how the student could measure the volume of the small toy.

You may use a diagram if it helps your answer.

The student uses the equipment shown in Figure 2 to measure the temperature of water as it is heated.

Figure 2

Describe an experiment the student could carry out to determine the specific heat capacity of the water.