1Mixtures-a blend of two or more substances
When we classified matter, we learned that mixtures can be classified as:
Homogeneous (visually the same throughout) or Heterogeneous visually different throughout)
What are some examples of each of these types of mixtures?
2Suspension: a heterogeneous mixture of
2 or more substancesParticles are large enough to settle out and can be separated by filteringi.e. – Muddy water
Colloid3
Colloids: homogeneous mixture of 2 or more substances evenly blended into one another.Substances never
separate (settle out)
4A solution is...Def. - A homogenous mixture of two
or more substancesThe Formation of a solution is a physical change …NOT a chemical
change.Ex. Saltwater, Kool-aid (sugar in H2O)
5
Solute: the substance that is being dissolved •Present in the smallest amount
Solvent: component present in the largest amount (usually H2O).
6Types of Liquid SolutionsAqueousA solution with water as
the solvent ex. Saltwater, Kool-aid
TinctureA solution with alcohol
as the solvent ex. camphor
7Concentrated vs. Dilute
A concentrated solution contains:Large amount of SOLUTE in a
small amount of SOLVENT
A dilute solution contains:Small amount of SOLUTE dissolved in a large amount of SOLVENT
“from concentrate”
SUMMARY
8Solution Concentration Refers to the amount of solute
dissolved in a solvent 5 grams of salt in 100 grams of
waterdiluteVS
35 grams of salt in 100 grams of
waterconcentrated
100 g.
100 g.
5 g
35 g
9
Solid into a Solid-Alloy: two metals dissolved into one another. Ex. steel= iron + carbon
Solid into a Liquid: Salt dissolved in water.Gas into a Liquid: CO2 dissolved (under pressure) into a soda.
10Dissolving the process of creating a solution
through the mixing of solute and solvent particles
Can a solute be dissolved by any solvent? NO!!
11Insoluble When a substance cannot be dissolved in a solvent...
Oil water+ =
The word soluble refers to solutes that CAN be dissolved in a
particular solvent.
12SolubilityA measure of how much solute
can be dissolved in a solvent under certain conditions (i.e. – temp. & pressure)
Example
133 Types of Solubility
Saturated: the maximum amount of solute has been dissolved in the solvent ex. Cup of water w/most salt that will dissolve w/out seeing salt on bottom
Unsaturated: more solute can be dissolved in the solvent ex. Cup of water with one spoon of salt
Supersaturated: more solute has been dissolved than is normally possibleEx. Cup of water w/so much salt in it, salt is on bottom
14Solubility Graphs
Solubility of KCL
0
10
20
30
40
50
60
0 20 40 60 100
Supersaturated
Unsaturated
Saturated
Unsaturated
Supersaturated
15
Any point directly on the line = Saturated
Any point below the line = Unsaturated
Shows the relationship between temperature and solubility
16Dissolving Rate
Def. – The amount of time required for a solvent to dissolve a particular solute
“Speed of dissolving”
17Three Factors Affecting Dissolving Rate of a Solid into a Liquid:
1.Temperature
2. Stirring
3. Surface Area
18Temperature Increasing the temperature
causes an increase in kinetic energy of the solid solute and liquid solvent particles
As the particles move faster, they collide into each other more, thereby increasing the DISSOLVING RATE
19StirringStirring also increases
dissolving rate
Stirring causes an increase in collisions between the particles in a solution
20Surface Area Def. – A measure of how much
exposed area a substance has Breaking, crushing, etc. are ways to
increase the Surface Area Increasing surface area allows more
solute to come into contact with the solvent; increases dissolving rate
VS.
Solubility of Gases 21
Pressure has the greatest effect on the solubility of a
gas in a liquid!
Depends on:1. Pressure = solubility2. Temperature= solubility3. Stirring = solubility