Topic 14 - Particle model Flashcards
The kinetic theory shows
In each state, the kinetic energy levels of the particles are different which causes the physical changes
Solid: Strong forces of attraction and low kinetic energy.
Liquid:Weaker forces of attraction, more energy in kinetic stores
Gas:No forces of attraction, high kinetic energy
Density(kg/m^3) = `
Mass(kg) / Volume(m^3)
Practical for investigating density of objects
Weigh the object
Fill eureka can as much as possible so it doesnt come out the spout
Place measuring cylinder below spout
Add object to eureka can and let water fall out of spout.
Measure the amount of water in the measuring cylinder
This is the volume of the object, which can be used with mass to calculate density
What changes and doesnt change when there is a change in state
Density changes but mass doesnt
When a system is heated,
Internal energy will increase, or there will be a change in state
Specific heat capacity(SHC) is
The change in energy in a substances thermal store needed to raise the temp of 1kg by 1*C
Specific latent heat(SLH) is
The amount of energy needed to change 1kg of a substance from one state to another without changing its temperature
Specific heat capacity equation:
Change in thermal energy(J) = Mass(kg) x SHC(J/kgC) x Change in temperature(C)
Specific latent heat equation:
Thermal energy for a change in state(J) = Mass(kg) x SLH(J/kg)
How to find the SHC of water
Measure mass of insulating container
Fill with water and measure again
Use joulemeter connected to electric immersion heater
Measure tmp of water, the nturn on and heat up water to specific point
Use mass of water, temp change and thermal energy used to calculate SHC
How to show SLH of water
Fill beaker with crushed ice
Place thermometer in ice and record temperature
Graduallly heat beaker full of ice
Every 20 seconds, measure temp and current state of ice
Continue until it starts to boil
Plot temp/time graph and it should show flat lines of temp when the stateis changing
Pressure of a gas is created by
Constant collisions which exert a force on the container
The speed of gas particles depends on
Temperature
Higher temp means higher
Pressure
Increasing volume means
Lower pressure because the space inhabited is higher and the mass stays the same
Pressure and volume are
inversely proportional
Absolute zero is
The coldest possible temperature something can get to
Absolute zero is because
When particles reach this temperature, they have the lowest possible amount of kinetic energy so arent moving. It isnt possible to take any more energy, so impossible to have a lower temperature
Absolute zero temperature
-273*C or 0 kelvin
To convert from *C to kelvin
Add 273
Increases in pressure in containers without a fixed volume leads to
The gas expanding until the inside pressure is equal to the outside pressure again
Pressure of a gas produces a net force at
right angles to any surface
Pressure before x Volume before =
Pressure after x Volume after
Doing work on a gas can
Increase its temperature
