Particles Flashcards
Is a change of state physical or chemical
Physical- no new substances produced
(Mass always stays same)
How to calculate density
Density = mass/ volume
What is density measured in
Kg/ m cubed
What is the temperature of a substance based on
Average kinetic energy of its particles
True or false, temperature changes during change of state
False- it doesn’t change
What is internal energy
Total kinetic and potential energy of particles in substance
What is potential energy
How far away particles are
More heat= particles further away= more potential energy
What is density a measure of
How much mass there is in a given volume of a substance
Density= mass/ volume
What special piece of equipment is used to find volume of irregular object
Eureka can
Name of change of state from gas to solid
Deposition
Name of change of state from solid to gas
Sublimation
Sublimation vs deposition
Both= changes of state
Deposition= gas to solid
Sublimation= solid to gas
Evaporation vs boiling (both changes of state from liquid to gas)
Evaporation:
No bubbles
Happens at surface of liquid
Happens at temperatures below boiling point
Boiling:
bubbles
Happens throughout liquid
Only happens at boiling point temperature
Why does temperature increase when a substance is heated (without changing its state)
Particles gain kinetic energy and move faster
This increases temperature as temperature is average kinetic energy of the particles in the substance
What is specific latent heat
Energy required to change state of 1kg of substance without changing its temperature
Examples of specific latent heat
Boiling water
Melting ice
Thermoregulation (sweat evaporating)
2 types of specific latent heat
Fusion (melting/ freezing)
Vaporisation (boiling/ condensing)
Which needs more energy, specific latent heat of fusion or vaporisation
Vaporisation
Equation linking specific latent heat, energy and mass
Specific latent heat = energy/ mass
Specific latent heat of fusion meaning
Energy required to melt/ freeze 1kg of substance without changing its temperature
Specific latent heat of vaporisation meaning
Energy required to boil/ condense 1kg of substance without changing its temperature
What is pressure in a gas created by
Particles colliding randomly with walls of container and exerting a force
They collide at right angles to container walls
They move in straight lines but randomly
Relationship between pressure and temperature (when mass and volume of gas in sealed container is constant)
Pressure increases proportionally to temperature
Relationship between pressure and volume of gas (at fixed mass and constant temperature)
Inversely proportional
If volume doubles then pressure halves etc
Which out of chemical and physical changes can easily be reversed
Physical but not chemical
True or false, mass remains constant during both chemical and physical changes
True
Why does pressure increase if temperature of gas increases in sealed container (volume is constant)
Particles move faster so hit surfaces with more force
Number of these impacts per second increases so more overall force
Equation linking pressure, volume and constant
Pressure= constant/ volume
Why does temperature of gas increase when it’s compressed quickly
Requires force to be applied to gas so work is done on gas
This energy gained by the gas isn’t transferred quickly enough to the surroundings
Latent heat of vaporisation vs fusion
Fusion is energy required to melt
Vaporisation is energy required to evaporate
Particles in a gas are constantly moving in… directions at… speeds
Random
Explain why if volume of fixed mass of gas at constant temperature decreases pressure increases
Particles travel less far to collide with walls of container
So more impacts (collisions) per second and total force of impact increases
Vice versa if volume increases where pressure would then increase
Equation linking pressure, volume and constant
Pressure x volume = constant
(Pressure and volume are inversely proportional)
