Solids, Liquids and Gases Flashcards
State the SI units for temperature
C - celcius
K - kelvin
State the SI unit for Force
N
State the SI unit for Mass
Kg
State the SI unit for density
Kg/m3
State the SI unit for pressure
Pa
State the SI unit for specific heat capacity
J/kgC
State the formula for density
Density = mass/volume or ρ = m/v
State the formula for volume
Volume = width x length x height
State the formula for static pressure
Pressure = force/ area or P=F/A
How does pressure act in liquids and gases?
It acts equally in all directions (not just downwards)
State the formula for pressure difference at different depths in liquids
Pressure = height x density x gravitational field strength p = h x ρ x g
Describe the arrangement and motion of particles in a solid
least kinetic energy
regular arrangement
vibrate about a fixed point
coldest
Describe the arrangement and motion of particles in a liquid
Can move past each other
Disorganised
Describe the arrangement and motion of particles in a gas
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
State something about proportion with temperature and kinetic energy
(absolute) temperature is proportional to the average kinetic energy of the particles in a substance
State something about pressure and gas
Since the gas particles exert a force on the walls of their container, they also exert pressure since pressure = force/area
What happens when the temperature of a gas is increased?
The kinetic energy/speed of the particles increases
State the lowest temperature possible
0 Kelvin or -273C
What is zero Kelvin called?
Absolute zero - at this temperature particles stop moving and there is no pressure (since they don’t collide with the walls of the container)
Describe how for a fixed volume, what happens if the temperature increases
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)
State the relationship between kelvin and pressure
Doubling the temperature in kelvin doubles the pressure
State the equation linking kelvin and pressure
P1 x T2 = P2 T1
State the relationship between halving volume and pressure
(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
State the equation linking volume and pressure
P1 x V1 = P2 x V2
State the relationship between heat energy and temperature change
When heat energy is added to a system, it will either increase the temperature or produce a change of state
Describe the changes that occur during melting
The energy is being used to break the bonds between the molecules. (temp./kinetic energy stays the same)
Describe the changes that occur during boiling
The energy is being used to overcome the attractive forces and break the bonds between the molecules. (Temp./kinetic energy stays the same)
Describe an experiment to show that temperature remains constant during a change of state
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
What is specific heat capacity?
Specific heat capacity is the energy required to change the temperature of an object by one degree Celsius per kilogram of mass (J/KgC)
State the formula to find the change in thermal energy
Change in thermal energy = mass x specific heat capacity x change in temp. or ΔQ = m x c x ΔT
Describe an experiment to determine the specific heat capacity of materials
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
State the difference between accuracy and precision
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)
Explain why a measurement might not always be accurate
Instrument not calibrated properly (not zeroed)
Scale is wrong
Parallax error - not on flat surface or not reading eye level/ user error
State Boyles Law
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
