Properties of Matter

Question 1

What is meant by pressure?

Answer 1

The force per unit area

Question 2

Using Kinetic Theory explain what happens to the pressure if you increase the temperature of a fixed mass gas in a fixed volume container?

Answer 2

The temperature is increased and particles gain kinetic energy.

They will hit the sides of the container more often and with a greater velocity and so greater force.

Pressure increases.

Question 3

These two block of wood have identical mass. Explain which exerts the greatest pressure.

Answer 3

• Both blocks have the same mass, so as W=mg will exert the same force down on the surface.
• Block B is sitting so that a small area sits on the surface, so as P = F/A it will exert a larger pressure.

Question 4

A temperature - time graph is shown below.
What is happening at each point on the graph?

Answer 4

A-The temperature of the solid is increasing

B-Change of state from solid to liquid

C-The temperature of the liquid is increasing.

D-Change of state from liquid to gas

E-The temperature of the gas is increasing.

Question 5

What is specific heat capacity?

Answer 5

Energy is required to heat 1kg of a substance by 1^OC.

Question 6

Using Kinetic Theory explain what happens to the pressure if you decrease the volume of a fixed mass gas at a constant temperature?

Answer 6

• Pressure is caused by the force of particles hitting the sides of the container.
• The volume is decreased. The particles have less room to move about and so hit the sides of the container more often creating a larger force.
• So the pressure increases.

Question 7

What is latent heat of fusion?

Answer 7

The number of Joules of energy required to change 1kg of a solid to 1kg of a liquid with no temperature change.

Question 8

Describe an experiment to investigate the relationship between the the pressure and the volume of a fixed mass of gas, at a constant temperature.

Answer 8

Boyles Law:

• Pump is used to put pressure on oil which puts pressure on a fixed mass of trapped gas.
• Valve is closed.
• Volume of air column is read off the scale.
• Pressure is read off the bourdon gauge.
• Valve is opened and closed to change the pressure to get a set of readings.
• Draw graph of pressure against volume.

Question 9

How can you convert between ^OC (degrees Celsius) and K (Kelvin)?

Answer 9

Temperature in degrees Celsius + 273

Question 10

What is conservation of energy?

Answer 10

Energy cannot be created or destroyed it can only be transferred from one type to another.

Question 11

Explain how snow shoes prevent you sinking into the snow.

Answer 11

Snow shoes have a large area. So the force of the person (weight) is spread over a larger area so the pressure exterted on the snow is less as P = F/A

Question 12

What temperature does absolute zero occur at?

Answer 12

0 K or -273 ^OC.

Question 13

Describe an experiment to investigate the relationship between the temperature and the pressure of a fixed mass of gas, with a fixed volume.

Answer 13

• Place the flask in a beaker of water.
• Heat the water.
• As the water heats up take a set of readings.
• The temperature of the water from the thermometer
• The pressure of the gas from the bourdon gauge
• Draw graph of pressure against temperature

Question 14

What causes pressure of a gas in a container?

Answer 14

Gas particles hitting the sides of a container

Question 15

What is latent heat of vaporisation?

Answer 15

The number of Joules of energy required to change 1kg of a liquid to 1kg of a gas with no temperature change.

Question 16

What is meant by absolute zero?

Answer 16

• When gas particles have no energy and cannot move or collide with the sides of the container.
• They have no more kinetic energy to remove.
• Temperature cannot go below this.

Question 17

Using Kinetic Theory explain what happens to the volume if you increase the temperature of a fixed mass gas at a fixed pressure?

Answer 17

• Pressure is caused by the force of particles hitting the sides of the container.
• The temperature is increased. The particles gain kinetic energy.
• They will move faster and so hit the sides of the container more often and with a greater velocity and so greater force.
• So the pressure increases.
• This puts pressure on a rubber bung/bead of mercury etc. and it moves. It will move until the pressure inside the container = pressure outside the container.
• So the volume will increase.

Question 18

What is the energy change in a buzzer?

Answer 18

Electrical to sound

Question 19

What is meant by heat?

Answer 19

It is the energy of the substance.

Question 20

Suggest a way that we say ‘energy is lost’ (not converted to the type of energy we want)?

Answer 20

• Heat lost to the surroundings due to friction
• Sound energy lost to air because of vibrations
• Energy lost as heat to the surroundings
• Heat lost in heating up a container instead of the substance in it

Question 21

Explain why being stood on by a stilletto heel is painful.

Answer 21

Stileto heels have very small areas. So the force of the person (weight) is spread over a very small area so the pressure exterted is high as P = F/A

Question 22

What is meant by temperature?

Answer 22

It is a measure of the mean kinetic energy of the particles.

Question 23

Describe an experiment to investigate the relationship bewteen the volume and the temperature of a fixed mass of gas at a fixed pressure.

Answer 23

• A fixed mass of gas is trapped by a bead of mercury
• Place the capilary tube, thermometer and ruler/scale into the beaker of water.
• Heat the water.
• At different temperatures - measure the temperature of the gas from the thermometer and the volume from the ruler/scale.
• The pressure is kept constant as the bead of mercury is free to move so that the pressure reamins constant.
• Plot a graph of volume against temperature.

Question 24

Two 1kg blocks of metal are heated up. Block A and Block B. Each block is made from a different material. They are both supplied with 10000J on energy. Block B has the biggest temperature change.

What can you say about Block B compared to Block A?

Answer 24

Block B has a lower specific heat capacity.