P6 Particles Flashcards
state the equation for specific heat capacity
change in energy = mass x SHC x change in temp
∆E = m x c x ∆θ
(J) (kg) (J/kg) (°C)
define specific heat capacity
the amount of energy needed to change the temperature of 1kg of a substance by 1 degree C
describe the method for RP: measuring specific heat capacity of a material
describe the methods (2) for RP: calculating density of irregular solid objects
- measure mass of object using balance
- fill eureka can with water
- make water level with spout
- place object in water
- collect displaced water in a measuring cylinder
- volume of water in measuring cylinder = volume of object
- calculate density using mass / volume
OR - measure mass of object using balance
- fill measuring cylinder with water so object will be submerged
- record starting volume of water
- place object in water
- record new volume of water
- new volume - starting volume = volume of object
- calculate density using mass / volume
describe the method for calculating density of a regular solid object
- measure length, width and height of object using a ruler
- calculate volume by multiplying all figures together
- measure mass of object using a balance
- calculate density = mass / volume
state the equation for density
density = mass / volume
p = m / V
(kg/m³) (kg) (m³)
-> solids+liquids are denser than gases as atoms are closely packed together, so there is a lot of mass in a small volume
state the equation for specific latent heat
change in energy = mass x latent heat
∆E = m x L
(J) (kg) (J/kg)
define specific latent heat
amount of energy required to change the state of 1kg of a substance without a change in temp
solid-liquid : SLH of melting
liquid-gas : SLH of vaporisation
define sublimation and deposition
- sublimation - change of state from solid to gas
- deposition - change of state from gas to solid
describe how to increase gas pressure in a container
- decrease volume of the container - distance for particles to travel is reduced so there are more collisions per second with the container walls+ other particles
- increase temperature - particles gain more kinetic energy so move faster+ exert greater force on container walls+ more collisions occur
describe the arrangement+motion of particles in a solid
- packed tightly together
- in orderly rows - regular arrangement
- high density
- vibrate in fixed positions
- solids have a fixed shape as particles cannot move from place to place
- cannot be compressed+ have a fixed volume as particles have no space to move to
- due to strong attractive forces between particles
describe the arrangement+motion of particles in a liquid
- loosely packed - particles can move freely
- random arrangement
- liquids can flow+ take the shape of their container as particles can move past each other
- cannot be compressed+ have a fixed volume as particles keep close contact+ have no space to move to
- due to weaker attractive forces (than solids) between particles
describe the arrangement+motion of particles in a gas
- particles are far apart
- random arrangement
- move quickly at different speeds+ different directions
- due to weak attractive forces between particles
- completely fill their container as particles move in all directions+ aren’t touching
- no fixed shape or volume
- can be compressed as particles have space to move to - low density
state limitations of the particle model for solids/liquids/gases
- particles are not actually solid spheres
- forces between particles are not represented
