Solids, Liquids and Gases

Question 1

State the SI units for temperature

Answer 1

C - celcius

K - kelvin

Question 2

State the SI unit for Force

Answer 2

N

Question 3

State the SI unit for Mass

Answer 3

Kg

Question 4

State the SI unit for density

Answer 4

Kg/m3

Question 5

State the SI unit for pressure

Answer 5

Pa

Question 6

State the SI unit for specific heat capacity

Answer 6

J/kgC

Question 7

State the formula for density

Answer 7

Density = mass/volume or ρ = m/v

Question 8

State the formula for volume

Answer 8

Volume = width x length x height

Question 9

State the formula for static pressure

Answer 9

Pressure = force/ area or P=F/A

Question 10

How does pressure act in liquids and gases?

Answer 10

It acts equally in all directions (not just downwards)

Question 11

State the formula for pressure difference at different depths in liquids

Answer 11

Pressure = height x density x gravitational field strength 
p = h x ρ x g

Question 12

Describe the arrangement and motion of particles in a solid

Answer 12

least kinetic energy
regular arrangement
vibrate about a fixed point
coldest

Question 13

Describe the arrangement and motion of particles in a liquid

Answer 13

Can move past each other

Disorganised

Question 14

Describe the arrangement and motion of particles in a gas

Answer 14

Most kinetic energy
Random
Rapid/ fast
Big spaces
Exert a force on the walls of their container, they also exert pressure since pressure = force/area

Question 15

State something about proportion with temperature and kinetic energy

Answer 15

(absolute) temperature is proportional to the average kinetic energy of the particles in a substance

Question 16

State something about pressure and gas

Answer 16

Since the gas particles exert a force on the walls of their container, they also exert pressure since pressure = force/area

Question 17

What happens when the temperature of a gas is increased?

Answer 17

The kinetic energy/speed of the particles increases

Question 18

State the lowest temperature possible

Answer 18

0 Kelvin or -273C

Question 19

What is zero Kelvin called?

Answer 19

Absolute zero - at this temperature particles stop moving and there is no pressure (since they don’t collide with the walls of the container)

Question 20

Describe how for a fixed volume, what happens if the temperature increases

Answer 20

If the temperature increases then the pressure increases due to -
Increased speed of collision (with the walls of the container) and hence increased force
Increased rate/ frequency of collision (with the walls of the container)

Question 21

State the relationship between kelvin and pressure

Answer 21

Doubling the temperature in kelvin doubles the pressure

Question 22

State the equation linking kelvin and pressure

Answer 22

P1 x T2 = P2 T1

Question 23

State the relationship between halving volume and pressure

Answer 23

(For a fixed temperature) Halving the volume of container doubles the rate of collision (with the walls of the container) and hence doubles the pressure

Question 24

State the equation linking volume and pressure

Answer 24

P1 x V1 = P2 x V2

Question 25

State the relationship between heat energy and temperature change

Answer 25

When heat energy is added to a system, it will either increase the temperature or produce a change of state

Question 26

Describe the changes that occur during melting

Answer 26

The energy is being used to break the bonds between the molecules. (temp./kinetic energy stays the same)

Question 27

Describe the changes that occur during boiling

Answer 27

The energy is being used to overcome the attractive forces and break the bonds between the molecules. (Temp./kinetic energy stays the same)

Question 28

Describe an experiment to show that temperature remains constant during a change of state

Answer 28

Put some stearic acid in a test tube with a thermometer and some wool plugging the top
Attach it to a clamp attached to a clamp stand
Record the temperature every minute
You will notice that as it changes state the temperature remains the same

Question 29

What is specific heat capacity?

Answer 29

Specific heat capacity is the energy required to change the temperature of an object by one degree Celsius per kilogram of mass (J/KgC)

Question 30

State the formula to find the change in thermal energy

Answer 30

Change in thermal energy = mass x specific heat capacity x change in temp. or ΔQ = m x c x ΔT

Question 31

Describe an experiment to determine the specific heat capacity of materials

Answer 31

Equipment:
Thermometer
Ammeter
Voltmeter
Heater
Timer
Aluminium block

Record:
Starting temp.
Final temp.
Time taken
Voltage
Current
Material
Mass of material

Calculate:
Energy supplied to heat the block- energy supplied = current x voltage x time

Determine specific heat capacity for material- C = ΔQ/ m x ΔT

Question 32

State the difference between accuracy and precision

Answer 32

Precision - an indication of the smallest increment that can be measured
Accuracy - An indication of how close a measurement is to its actual value (for the given level of precision)

Question 33

Explain why a measurement might not always be accurate

Answer 33

Instrument not calibrated properly (not zeroed)
Scale is wrong
Parallax error - not on flat surface or not reading eye level/ user error

Question 34

State Boyles Law

Answer 34

If you keep a gas at constant temperature, but halve the volume
The particles move at the same speed (same temperature means same kinetic energy)
But they collide with the walls of the container twice as often
- Halve the volume, double the pressure

For a fixed mass of gas at a constant temperature-
P1 x V1 = P2 x V2