Particle model of matter - Paper 1

Question 1

State the equation with all units for density

Answer 1

Density = mass / volume

Density - kg/m³

mass - kg

Volume - m³

Question 2

How can the density of a regular shaped object be found?

Answer 2

Find mass using an electronic balance.

Find volume using a ruler to measure the length of each side

Then the equation volume = l x l x l

Use the density equation Density = mass / volume

Question 3

How can the density of a irregular shaped object be found?

Answer 3

Find mass using an electronic balance.

Find volume using a eureka can

Use the density equation Density = mass / volume

Question 4

How can a eureka cab be used to find the volume of an irregaulr object?

Answer 4

Fill the eureka can with water

Place the object in the water.

The volume of water will rise by the exact volume as the object.

Collect the dispalced volume of water and measure with a measuring cylinder.

Question 5

How can the density of a liquid be found?

Answer 5

Find the volume using a measuring cylinder

Place an empty measuring cycling on an electronic balance and record the mass.

Add the liquid and record the new mass.

calculate the mass of the liquid (new mass - old mass)

Use the density equation Density = mass / volume

Question 6

Describe the state changes in melting

Answer 6

Solid to liquid

Question 7

Describe the state changes in freezing

Answer 7

Liquid to solid

Question 8

Describe the state changes in evaporating

Answer 8

Liquid to gas

Question 9

Describe the state changes in condensing

Answer 9

Gas to liquid

Question 10

Describe the state changes in sublimation

Answer 10

Solid to gas (missing out the liquid stage)

Question 11

Define internal energy

Answer 11

Energy is stored inside a system by the particles

Question 12

State the equation for internal energy

Answer 12

Internal energy = Kinetic energy + potential energy

Question 13

Why does heating always increase internal energy

Answer 13

Heating will either cause the substance to heat up and its kinetic energy to increase or the substance will change state and the internal energy will increase

Question 14

If a substance is heating up what factors affect the increase in temperature?

Answer 14

1. The mass of the substance
2. The material ( the specific heat capacity)
3. The rate at which energy is supplied

Question 15

Define specific heat capacity

Answer 15

The specific heat capacity of a substance is the amount of energy required to raise the temperature of one kilogram of the substance by one degree Celsius.

Question 16

State the units for specific heat capacity

Answer 16

J/kg °C

Question 17

When a substance changes state why doesn’t the temperate rise?

Answer 17

All the energy is being used to break the bonds and increase the internal energy

Question 18

Define specific latent heat

Answer 18

The specific latent heat of a substance is the amount of energy required to change the state of one kilogram of the substance with no change in temperature.

Question 19

State the difference between the latent heat of fusion and vaperisation

Answer 19

latent heat of Fusion is when a solid changes to a liquid

latent heat of Vaporisation is when a liquid changes to a gas

Question 20

State the units of latent heat

Answer 20

J/kg

Question 21

Describe the motion of gas particles

Answer 21

constant random motion

Question 22

As a gas is heated how does the particle motion change?

Answer 22

Particles move faster as they have more kinetic energy

Question 23

What causes gas pressure

Answer 23

Moving gas particles colliding with a container/object. This pressure will always create a force at a right angle to the container.

Question 24

Explain the relationship between the temperature of a gas and its pressure?

Answer 24

As temperature increase the pressure increases. this is because the particles have more kinetic energy and move faster. This means there are more collisions each second

Question 25

State the units of pressure

Answer 25

Pascals (Pa)

Question 26

If the volume of a container increases what effect will this have on pressure?

Answer 26

As volume increase pressure decreases. It is an inversely proportional relationship. A large volume will mean less collisions per second

Question 27

When work is done on a gas trying to compress it how does this affect the temperature and internal energy

Answer 27

Work done on the gas makes the particels move faster so they gain kinetic energy. This increases internal energy.

Question 28

What is the average kinetic energy of the molecules related to?

Answer 28

The temperature of a gas

Question 29

What happens to kinetic energy if the temperature of a substance is increased?

Answer 29

The total kinetic energy of the particles increases and so the internal energy increased

Question 30

What is latent heat?

Answer 30

The energy transferred to or from a substance when it changes state

Question 31

What happens to the temperature of a substance during change of state?

Answer 31

The temperature is constant, so the total kinetic energy of particles does not change

Question 32

What type of energy changes during a change of state

Answer 32

Potential energy so internal energy must increase as well

Question 33

While water changes state how could you estimate the power of a Bunsen burner?

Answer 33

Measure the mass of the water that boils.

Calculate the energy transferred to the water using E = mL

Calculate the power using power = energy/time

Question 34

While water is being heated up how could you estimate the power of a Bunsen burner?

Answer 34

Measure the temperature increase of the water.

Calculate the energy transferred to the water using E = mass x shc x temperature change.

Calculate the power using power = energy/time