Rate of Dissolving
A _________ dissolves in a _________
to form a ___________
video
Allergies?
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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 is used to dissolve carbon dioxide gas in liquid pop
Pressure forces gas particles into the spaces between the
liquid particles
gas
So…
More pressure = Dissolve Faster
Pressure
Altitude Sickness and
Nitrogen Narcosis
(“The Bends”)
Video
Matter
Heterogeneous
materials - can see two parts
Homogeneous materials
can see only one thing - one set of
properties
Mechanical Mixture
Homogeneous
mixtures
They’re mixed together so well you only
see one thing – it looks pure but it isn’t
Solution – made when a
Pure substances
You can only see one thing because
there is only one kind of particle in it.
- Temperature, Stirring, Particle
Size and Pressure speed this
solute dissolves in a solvent
up the dissolving rate