Rate of Dissolving

A _________ dissolves in a _________ to form a ___________

video

Allergies?

• May contain traces of:

• Peanuts

• Eggs

• Wheat

mmm Chocolate Science

mmm Chocolate Science Dissolving Time

NOT moving tongue or chewing

Stir with your tongue

Chewing

1. The chocolate ______________________ in the saliva in your mouth to form a _______________

2. Solutions contain two parts: ________________________ & _______________________

3. In this lab, the solute is the ________________________, and the solvent is the __________________

4. Since the chocolate dissolved in your mouth we can say it was _____________________

Factors Affecting How Fast a Solute Dissolves

1. Temperature

2. Stirring or Shaking

3. Crushing (Surface Area)

4. Pressure

1. Temperature

If we heat particles they will move faster

• The solvent will carry the solute particles away faster

So…

Hotter = Dissolve Faster

2. Stirring or Shaking

Stirring or shaking a solution moves the solute particles around so that they are closer to water particles

• the water particles can then attract them easily and carry them away!

So…

Stir or Shake = Dissolve Faster

3. Crushing (Surface Area)

When a sugar cube is broken into small pieces, the individual sugar particles can get closer to water particles

• the water particles can then attract them easily and carry them away!

Dissolving happens on the surface of particles

• When solute is broken up, there is more surface area where dissolving can occur

broken up

4. Pressure

Pressure forces gas particles into the spaces between the liquid particles

Pressure is used to dissolve carbon dioxide gas in liquid pop

gas

So…

More pressure = Dissolve Faster

Pressure

Altitude Sickness and Nitrogen Narcosis (“The Bends”)

Video

Heterogeneous materials - can see two parts

Matter

Homogeneous materials can see only one

thing - one set of properties

Homogeneous mixtures

They’re mixed together so well you only see one thing – it looks pure

but it isn’t

Pure substancesYou can only see one thing because there is only one kind of particle in

it.

Mechanical Mixture

Solution – made when a solute dissolves in a

solvent

- Temperature, Stirring, Particle Size and Pressure

speed this up the dissolving rate