P2P14 - Particle model

Question 1

What is the kinetic theory of matter?

Answer 1

The kinetic theory of matter states that all matter is made up of tiny particles that are constantly moving.

Question 2

What states can be compressed?

Answer 2

Gases (liquids too?)

Question 3

Whats the mass of a substance that changed state?

Answer 3

The same as it was before (Mass was conserved)

Question 4

Who discovered that particles are constantly moving?

Answer 4

Robert Brown

Question 5

Whats the equation for density?

Answer 5

Density = Mass / Volume

Question 6

Why does an object float in a fluid?

Answer 6

If the density of the object is lower than the density of the fluid it floats.

Question 7

Whats the force that keeps an object afloat?

Answer 7

Upthrust

Question 8

What does the law of displacement say?

Answer 8

The Law of Displacement says:
An object fully submerged in a fluid will replace an amount of fluid equal to its own volume.

Question 9

What the units for density?

Answer 9

Kg/m3 or G/cm3

Question 10

Whats the equation for mass?

Answer 10

Mass = Density X Volume

Question 11

How do we find the measurements to find the density of irregularly shaped solids?

Answer 11

For solids, we can use the Law of Displacement to estimate its volume.

1. Measure the mass of a solid using a balance (scales).
2. Fill a displacement can with water.
3. Gently lower the solid into the can and allow the water to overflow into a measuring cylinder.
4. Measure the volume (amount) of this water that overflows because this is also the volume of the object.
5. Calculate density by dividing the object’s mass by the volume.

Question 12

How do we find the measurements to find the density of liquids?

Answer 12

1. Place a measuring cylinder on a balance and set the reading to zero.
2. Pour the liquid into the cylinder and write down its mass and volume.

Then calculate the density.

Question 13

Who discovered the law of displacement?

Answer 13

Archimedes discovered the law of displacement in the bath.

Question 14

Whats the equation for change in internal heat energy?

Answer 14

Change in internal energy =
Mass X Specific heat capacity
X Temperature change
ΔE = m × c × ΔT

Question 15

Whats the equation for Thermal capacity?

Answer 15

Thermal capacity =
Mass X Specific heat capacity

C = m × c

Question 16

What is latent heat?

Answer 16

The energy that is transferred to a substance without the substance’s temperature changing. This happens when a substance is changing state.

Question 17

What are the conditions for absolute zero?

Answer 17

-273C or 0K

Question 18

How do you convert Celcius to Kelvin?

Answer 18

Add 273
100C = 373K

Question 19

How can you detect latent heat?

Answer 19

Using a joulemeter and measuring the energy supplied to change state

Question 20

How do particles move at Absolute zero?

Answer 20

They don’t move.

Question 21

What term is used to describe the hidden energy when a solid becomes a liquid or a liquid becomes a solid?

Answer 21

Latent heat of fusion

Question 22

Whats the equation for the change of energy in a change of state?

Answer 22

Energy = Mass X Latent heat (J/kg)
E = M X L

Question 23

Experiment for Specific Latent Heat of Fusion

Answer 23

Gently heat ice in a funnel until it melts. Then measure the mass of the melted ice.
Measure the amount of energy supplied by the heater using a joulemeter (this gives us the energy change).
Calculate the specific latent heat of fusion using our equation
specific latent heat = energy change ÷ mass.

Question 24

Experiment for Specific Latent Heat of Vapourisation

Answer 24

Measure the mass of water in a beaker.
Boil some water and then measure the mass of the water again.
Mass at the start - mass at the end = change in mass.
Measure the amount of energy supplied by the heater using a joulemeter (this gives us the energy change).
Calculate the latent heat of vapourisation using our equation
Specific latent heat = energy change ÷ change in mass.