states of matter

what is the arrangement, movement and energy of particles in solids?

• particles are closely packed in a regular arrangement

• particles vibrate around a fixed point

• strong forces of attraction

• lowest amount of kinetic energy

what is the arrangement, movement and energy of particles in liquids?

• particles are close together, spaces open and close as the particles move

• particles can move freely, they can slip and slide past each other

• weaker forces of attraction than solids

• more kinetic energy than solids

what is the arrangement, movement and energy of particles in gases?

• particles are far apart, big spaces between then

• particles move quickly and randomly in all directions

• weak forces of attraction

• most kinetic energy

what is the interconversion from a solid to a liquid?

melting

what is the interconversion from a liquid to a solid?

freezing

what is the interconversion from a liquid to a gas?

boiling/evaporation

what is the interconversion from a gas to a liquid?

condensation

what is the interconversion from a solid to a gas?

sublimation

what is the interconversion from a gas to a solid?

deposition

what happens when particles are heated for a change of state? (e.g. solid to liquid)

• particles gain energy

• they move faster

• they move further apart

• they can overcome the forces of attraction

what happens when particles are cooled for a change of state? (e.g. liquid to solid)

• particles lose energy

• they move slower

• they move closer together

what is the difference between evaporation and boiling?

evaporation is the change of state which occurs when a liquid changes to a gas at a temperature below its boiling point, whilst boiling occurs when a liquid changes to a gas at its boiling point.

how can diffusion of gases be explained?

• 
  the gas particles will move from a high concentration to a low concentration

• each particle will move randomly and collide with air particles

• eventually the gases will be evenly mixed

how can the dilution of coloured solutions be explained?

• the particles will move from a high to low concentration

• therefore particles will spread out until equilibrium is reached

• however this will happen slower than gases because liquid particles move slower and are less spread out

what is a solvent?

the liquid that dissolves a substance

what is a solute?

the substance that dissolves in the solvent

what is a solution?

a homogenous mixture that consists of a solute that is dissolved in a solvent

what is a saturated solution?

a mixture that contains the maximum amount of a solute that can dissolve in a solvent at any given temperature

what is diffusion?

the net movement of particles from an area of high concentration to an area of low concentration

what is solubility in g/100g of solvent

the mass of solute which must dissolve in 100g of solvent at that temperature to form a saturated solution

solubility (g/100g) = mass of solute/mass of solvent x 100

investigate the solubility of potassium nitrate in water at 40 degrees celsius

1. weigh an evaporating basin

2. heat a boiling tube of water to just above 40

3. add potassium nitrate to the water in the boiling tube and stir rapidly until no more of it will dissolve and there is undissolved solid left over

4. allow the solution to cool to exactly 40

5. pour some of the solution into the evaporating basin, making sure you only pour the solution and not the solid

6. weigh the evaporating basin and its contents

7. heat the evaporating basin and its contents to evaporate all the water

8. weigh the evaporating basin again

9. heat the basin and its contents again and re-weigh to make sure all the water has evaporated