Properties of matter

Question 1

What is specific heat capacity?

Answer 1

The number of Joules of energy needed to raise 1kg of a substance by 1°C.

Question 2

What is meant by temperature?

Answer 2

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

Question 3

What is meant by heat?

Answer 3

It is the energy of the substance.

Question 4

What is conservation of energy?

Answer 4

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

Question 5

What is latent heat of vaporisation?

Answer 5

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

Question 6

What is latent heat of fusion?

Answer 6

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

Question 7

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

Answer 7

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 8

What is meant by pressure?

Answer 8

The force per unit area

Question 9

Explain how snow shoes prevent you sinking into the snow.

Answer 9

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 10

These two block of wood have identical mass. Explain which exerts the greatest pressure.
(One is flat and one is upright)

Answer 10

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 11

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

Answer 11

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 12

What causes pressure of a gas in a container?

Answer 12

Gas particles hitting the sides of a container

Question 13

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 13

Pressure is caused by 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 / force.
So the pressure increases.

Question 14

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

Answer 14

Pressure is caused by 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.
So the pressure increases.

Question 15

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

Answer 15

Pressure is caused by 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/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 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

What temperature does absolute zero occur at?

Answer 17

0 K or -273 °C

Question 18

How can you convert between °C (degrees Celsius) and K (Kelvin)?

Answer 18

Temperature in degrees Celsius + 273

Question 19

What is the energy change in a buzzer?

Answer 19

Electrical to sound

Question 20

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 20

Block B has a lower specific heat capacity

Question 21

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 21

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 21

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

Answer 21

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 22

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

Answer 22

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 23

What is a change from solid to liquid called

Answer 23

fusion

Question 24

What is a change from liquid to gas called

Answer 24

Vaporisation

Question 25

What is the equation for specific latent heat

Answer 25

Eh=ml

Question 26

What is the equation for specific heat capacity

Answer 26

Eh=cm x (change in)temp

Question 27

What is the specific latent heat

Answer 27

the heat energy required to change the state of a substance.

Question 28

What is the specific heat capacity

Answer 28

The amount of energy required to heat that substance by 1 degree Celsius.

Question 29

What is the area of a circle

Answer 29

Area of a circle = Pi x radius^2

Question 30

What is pressure

Answer 30

Pressure is force per unit area, so if you push on your desk with your hand, the pressure on the desk is the force in Newtons divided by the surface area of your hand.
P = F/A

Question 31

What is the degrees celsius equivalent of 0 Kelvin

Answer 31

-273 degrees celsius

Question 32

What is the Gay-Lussac’s Law

Answer 32

Gay-Lussac’s Law describes the relationship between pressure and temperature.

An increase in temperature increases pressure in a contained system. As temperature increases, the particles within the contained gas speed up. As these particles have increased kinetic energy, they hit off the sides of the container with more force. This causes an increased force on the surface area of the container, increasing pressure. The relationship is therefore directly proportional.

Question 33

What is the relationship between volume and temperature called

Answer 33

Charles’ Law.

Question 34

What is Charles’ Law.

Answer 34

When a gas is heated in a system with flexible boundaries, such as a closed syringe, or in a popcorn bag, temperature increases the volume of the gas. When the temperature of particles in the system increase, the particles gain more energy and collide with the surface of the container with more force. This causes the gas to expand within the container due to the increased force of the fast-moving particles. The relationship between temperature and volume is therefore directly proportional.

Question 35

What is the relationship between pressure and volume called

Answer 35

Boyle’s Law.

Question 36

What is Boyle’s Law.

Answer 36

When volume is decreased in a system, pressure increases. If the volume of a container is decreased, like compressing a balloon in the given image the number of particles in the gas remains the same. With the same number of particles and a decreased surface area, the particles will collide with the walls of the container more often. This will create more force per unit area, and thus increasing pressure. Therefore, this relationship is inversely proportional.