Title: Solutions!
1Solutions!
2Classification of Matter
3Heterogeneous Mixtures
- See visibly different regions
- Granite
- Dirt
- Cereals
- Oil Vinegar
- See a boundary
- Ice cube in water
4Homogeneous Mixtures
- Particles very small on atomic scale
- Cant see particles
- Cant sort particles
- Cant get trapped by filter
- Cant scatter light
- Particles evenly distributed
- Particles do not separate
5CuSO4(aq)
6Solution
- Homogeneous mixture of 2 or more substances in a
single physical state (phase)
7Parts of a Solution
- Solute dissolved substance
- Solvent dispersing medium
8Identify the solute and solvent in each picture
9(No Transcript)
10Hints to identify solute solvent
- Solute changes phase
- substance have less of
- Solvent maintains phase
- substance have most of
11Aqueous Solutions
- Water is solvent
- Transition metals form brightly colored solutions
12Solutions occur in all 3 phases!
13(No Transcript)
14CO2 in and out of water
Bubbles mean its a mixture not a solution!
15Alloys
16Soluble
- Soluble capable of being dissolved
- A substance that dissolves in another substance
is soluble - in that substance
17Insoluble
- A substance that does not dissolve in another
substance
18Amounts that can dissolve
- Solubility maximum amount of substance that
will dissolve in given amount of another
substance - LIMITS to amounts of most liquid/solid solutes
that will dissolve in given solvent - Temperature and pressure affect solubility
19Factors that affect the rate of dissolving
- Rate of dissolving is different from amount that
will dissolve! - Rate is how fast
- factors influence rate of dissolving
- Temperature
- Stirring or Agitation
- Surface Area of Solute
- Amount of solute already dissolved
20Dissolving
- Dissolving is physical change
- All physical chemical changes are accompanied
by changes in energy
21Equations for Dissolving
- C6H12O6(s) H2O(l)? C6H12O6(aq)
- NaCl(s)H2O(l) ? Na1(aq) Cl-1(aq)
22Covalent substances dissolve to produce molecules
in solution
23Ionic substances dissolve to produce ions in
solution
24Solvation
- Interaction between solvent molecules and solute
particles - Solute particles surrounded by solvent particles
in dissolving process - Solute particles may be ions, polar molecules, or
nonpolar molecules - Solvent molecules may be polar or nonpolar
25Hydration
- Specific name for solvent-solute interaction when
solvent is water
26Hydration of chloride ion Also called
molecule-ion interaction
27Solute-solvent interaction must be greater than
interaction between solute particles
for dissolving to occur
28(No Transcript)
29Solubility
- Amount solute that will dissolve in specific
solvent at given TEMPERATURE and PRESSURE - Amount can be determined experimentally
- Units
- grams solute per 100 grams solvent
30(No Transcript)
31(No Transcript)
32Why do you see bubbles form on the side of the
beaker as the water warms up? (Note its not
hot enough to boil)
33Vocabulary Interlude
- Miscible two liquids that WILL MIX
- together in any amounts
- Water and ethanol are miscible in all proportions
- Immiscible Liquids that will NOT MIX
- Oil and water are immiscible
34(No Transcript)
35Types of Solutions
36Electricity
- What do you need to conduct electricity?
Mobile, charged particles!!!!
37Vocabulary Interlude
- Electrolyte
- substance that dissolves in water to form
solution that conducts electricity - ions in solution
- Nonelectrolyte
- substance that dissolves in water to form
solution that does not conduct electricity - neutral molecules in solution
38(No Transcript)
39Dilute vs. Concentrated
- Tells relative amount of solute in solvent
- Concentrated
- large amounts of solute
- Dilute
- small amounts of solute
40Which solution is most dilute? The most
concentrated? How do you know?
The stronger the color, the more concentrated the
solution
41(No Transcript)
42Which solution is more concentrated? More
dilute? What can you say about the of solute
particles in pictures b and c?
43Unsaturated Solution
- Less solute than maximum amount that will
dissolve at given temperature and pressure
44Saturated Solution
- No more solute will dissolve at given temperature
pressure - Solubility amount of solute required to form a
saturated solution
45The solution is saturated when the solute stops
dissolving
46Dynamic Equilibrium Saturated Solution
Microscopic level Rate of dissolving Rate of
recrystallization Macroscopic level No
apparent change
47Supersaturated Solution
- Contains more solute than saturated solution
- VERY unstable
- have to be clever to make these (need to use heat)
48Testing for saturation
- Toss crystal of solute into solution and see
what happens
493 possible results
Unsaturated solution
- Crystal dissolves
- Crystal sinks to bottom of solution
- Bam! Suddenly have lots of solid solute in
beaker
Saturated solution
Supersaturated solution
50(No Transcript)
51How do terms saturated, unsaturated
supersaturated fit in with the solubility curves?
- Saturated solutions have maximum solute that will
dissolve at given temperature - Any point on trace lines represent saturated
solutions - All points above trace lines represent
- supersaturated solutions
- All points below trace lines represent
- unsaturated solutions
52Characterize points A, B, C, D with respect to
the KNO3 trace using the terms dilute
concentrated, saturated, unsaturated, or
supersaturated
A,C concentrated supersaturated
53Summary of Dissolving
- Occurs at surface of solid
- Involves interaction between solute and solvent
- Interaction is called solvation
- If water is solvent, interaction is called
hydration - Involves changes in energy
54(No Transcript)
55Solubility Information
- Often presented in graphs
- Graph show number grams of substance that can
dissolve in water between 0oC and 100oC - Trace line represents saturated solution
- above trace line represents supersaturated
solutions - below trace line represents unsaturated solutions
56Solubility Graphs
- Traces have positive or negative slopes
- Most solids have positive slope
- the hotter the water, the more solute dissolves
- The colder the water, the less solute dissolves
- All gases have negative slope
- the hotter the water, the less gas dissolves
- The colder the water, the more gas dissolves