KINETIC THEORY AND

SOLUBILITY

Kinetic Theory

3 Basic “assumptions”

All matter is composed of small particles [molecules, atoms and ions]

The particles are in constant, random motion.

The particles are colliding with each other and the wall of their container.

Why is kinetic theory important? Solubility:

The Ability to Dissolve

DissolvingThe process of combining a solid and a

liquid into a solution.

SOLUBILITYIs a PHYSICAL change…

No new products are formed.

The ID of the substances never changes.

Two parts to a solution

Solvent: The medium that does the dissolving.

Solute: The substance being dissolved.

For example: Salt Water○ Which is which?

Dissolving example

Ex salt and WaterThe salt is composed of billions of NaCl

particles.The water is composed of individual water

molecules. The salt particles are pulled apart by the

water molecules and become distributed throughout the water.

The water removes layers of salt until the solid appears gone.

Factors that can affect solubility

Surface Area (particle size)

Agitation

Temperature

Sugar Cube lab!

Lets start dissolving!

Effects of particle size

The smaller the size of the solute, the faster they dissolve.

The smaller the size, the more surface area comes in contact with the solvent causing the dissolving to occur faster.

Stirring or Agitation Effects The more a solution is stirred or

agitated, the faster the rate of dissolving for a solid in a liquid

Stirring or agitation causes the molecules to collide and breakdown into solution faster.

Effects of Temperature

The higher the temperature, the faster the solute will dissolve

At higher temperatures more of the solvent molecules moving faster and colliding with the solute particles.

The collisions breakdown the solute, causing it to dissolve faster.