P3 - Particle Model of Matter

Define condensing

The loss of heat from a gas where particles lack the energy to overcome forces of attraction, reforming bonds into a liquid state.

What we should consider particles as?

Small, solid and inelastic spheres

In a closed system, changes in state won't change the...

mass

What will happen if a gas is heated in an expandable container?

It will increase in volume

What will happen if a gas is heated in a fixed container?

It will increase in pressure

Density =

mass/volume

Density definition

Mass per unit volume

Density units

kg/m^3 or g/cm^3

What happens to the temperature of a substance whilst it changes state?

It remains constant

Specific latent heat definition =

the energy required to change the state of 1kg of a substance

Specific latent heat =

energy/mass

SLH of vaporisation

Liquid to gas

SLH of fusion

Solid to liquid

Pressure =

force/area

Increase in temperature makes pressure...

increase

Increase in concentration makes pressure...

increase

Decrease in volume makes pressure...

increase

What three factors affect gas pressure?

Volume, concentration and temperature

Specific heat capacity definition

the energy required to raise the temperature of one gram of a substance by one degree Celsius

Change in thermal energy=

mass x specific heat capacity x temperature change

energy=

mass x specific latent heat

Describe the motion of particles in a solid.

particles vibrate

about fixed positions

What length do coarse particles have?

2500 - 10000 nm

Explain how the internal energy of an element changes as it turns from liquid to gas

- Potential energy of the particle increases

- Kinetic energy doesn't change as temperature doesn't change

- So the internal energy increases

What are the three ways to increase pressure in a gas in a fixed container?

Increase temperature, increase concentration, decrease volume