1-States of matter

1.1 Solids, liquids and gases 1.2 Diffusion

Properties of solids

• Particles are regularly arranged and packed closely together

• These atoms vibrate at a fixed position

• They have strong forces of interaction that keep them together

Properties of liquids

• Particles have some gaps between them

• Forces of interaction are less effective, the particles can move around each other

• Particles are randomly arranged

Properties of a gas

• Particles move at high speeds in all directions

• The particles are much further apart with almost no forces of interaction

What is kinetic energy (k.e)?

It’s the energy a particle possesses due to its motion

What’s potential energy (p.e)?

It’s the energy of a particle due to it’s test position

What ke do solids have?

Solids have no ke

What ke do liquids have?

They have minimal ke

What ke do gases have?

They have a far greater amount of ke

What pe do solids have?

They have a far greater amount of pe

What pe do liquids have?

They have a minimal amount of pe

What pe do gases have?

They have no pe

What is melting?

Melting is when a solid turns into a liquid due to an energy increase in it’s particles

What’s freezing?

It’s when a liquid turns into a solid due to an energy reduction in its particles

What’s melting point (m.p)?

It’s the temperature at which a solid melts

What’s freezing point (f.p)?

It’s the temperature at which a liquid freezes

What’s boiling?

• It’s when a liquid is heated so strongly that the particles move fast enough to overcome the forces of attraction between them.

• The stronger the forces of attraction between the particles the higher the b.p

What’s the key difference between evaporation and boiling?

• Evaporation is over a range of temperatures

• Boiling is at a fixed temperature (b.p)

What’s the difference between evaporation and boiling on where is occurs?

• Evaporation is only at the surface of the liquid

• Boiling occurs throughout the liquid

What’s the difference between evaporation and boiling on temperature required?

• Evaporation can happen at any temperature below bp

• Boiling only happens at the bp

What’s the difference between evaporation and boiling on speed?

• Evaporation is a slow process

• Boiling is a fast process

What’s the difference between evaporation and boiling on heat source?

• Evaporation may occur without direct heat

• Boiling requires continuous heating

What’s the difference between evaporation and boiling on bubble formation?

• Evaporation has no bubbles formed in the liquid

• Boiling has bubbles form and rise to the surface

Example of evaporation:

Drying clothes

Example of boiling:

Water boiling on a stove

What’s diffusion?

• It’s the spreading out of particles from a point of high concentration to low concentration

When does diffusion stop?

When particles spread out until there is equal concentration throughout the container.

Why is diffusion in liquids very slow?

• Because the particles in a liquid move more slowly than the particles in a gas

• The particles in a liquid also much closer together than those in a gas so there is less space for the particles to move without colliding with each other

Where does diffusion occur?

In a gas or a liquid

What is a solute?

It’s the substance that dissolves. (Sugar)

What is a solvent?

The liquid the solid dissolves in (water)

What is a solution?

The liquid formed from the solute dissolving in a solvent (sugar water )

What is a saturated solution?

• It’s a solution that contains as much dissolved solid (solute) as possible at a particular temperature

What’s the solubility of a solid in a solid at a particular temperature?

It’s the mass of solute which must be dissolved in 100g of solvent at that temp to form a saturated solution.

What are solubility curves?

The solubility of solids changes with temperature, this is represented with solubility curves. Solubility increases with time(dramatically or a little)