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Solutions. Definitions Types of Solution Solutions, Colloids, Suspensions Process of Dissolving Rate of Solution Concentration Solubility. Definitions. Homogenous Mixture – two or more substances which have the same composition throughout; uniform; in the same state of matter - PowerPoint PPT Presentation
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Solutions Solutions
DefinitionsTypes of SolutionSolutions, Colloids, SuspensionsProcess of DissolvingRate of SolutionConcentrationSolubility
DefinitionsDefinitions
Homogenous Mixture – two or more substances which have the same composition throughout; uniform; in the same state of matter
• Solutions, Colloids, Suspensions Heterogeneous Mixture – two or more
substances which have a mixture in which the ingredients are not uniformly dispersed.
• Fruity Pebbles
Definitions Definitions
Solution - Solution - homogeneous mixture of two or more substances
Solvent Solvent - present in greater amount
Solute Solute - substance being dissolved, present in smaller amount Solute
particles very small
Definitions Definitions
Solute Solute - KMnO4 Solvent Solvent - H2O
Hydrogen Bonds Attract Polar Water Molecules
Hydrogen Bonds Attract Polar Water Molecules
Types of Solutions Types of Solutions
Based on state of solvent. All solid-liquid-gas combos are
possible. EX: dental amalgam (alloy of silver,
mercury, etc.)• liquid solute, solid solvent• solid solution
Types of SolutionsTypes of Solutions
air O2 gas and N2 gas gas/gas
soda CO2 gas in water gas/liquid
seawater NaCl in water solid/liquid
brass copper and zinc solid/solid
Learning Check SF1Learning Check SF1
(1) element (2) compound (3) solution
A. water 1 2 3
B. sugar 1 2 3
C. salt water 1 2 3
D. air 1 2 3
E. tea 1 2 3
Solution SF1Solution SF1
(1) element (2) compound (3) solution
A. water 2
B. sugar 2
C. salt water 3
D. air 3
E. tea 3
Learning Check SF2Learning Check SF2
Identify the solute and the solvent.
A. brass: 20 g zinc + 50 g copper
solute = 1) zinc 2) copper
solvent = 1) zinc 2) copper
B. 100 g H2O + 5 g KCl
solute = 1) KCl 2) H2O
solvent = 1) KCl 2) H2O
Solution SF2Solution SF2
A. brass: 20 g zinc + 50 g copper
solute = 1) zinc solvent = 2) copper
B. 100 g H2O + 5 g KCl
solute = 1) KCl
solvent = 2) H2O
Dissolving Dissolving
SolvationSolvation
• occurs at the surface of the solute
• solvent particles surround solute particles (+/- attraction)
• solute particles are pulled into solution
Dissolving Dissolving
NaCl dissolving in waterNaCl dissolving in water
“Like Dissolves Like” “Like Dissolves Like”
NONPOLAR
NONPOLAR
POLAR
POLAR
DetergentsDetergents• polar “head” with long nonpolar “tail”• can dissolve both types
Learning Check SF4Learning Check SF4
Which of the following solutes will dissolve in water? Why?
1) Na2SO4
2) gasoline
3) I2
4) HCl
Like dissolves likeLike dissolves like
A ____________ solvent such as water is needed
to dissolve polar solutes such as sugar and
ionic solutes such as NaCl.
A ___________solvent such as hexane (C6H14)
is needed to dissolve nonpolar solutes such
as oil or grease.
Solution SF4Solution SF4
Which of the following solutes will dissolve in water? Why?
1) Na2SO4 Yes, polar (ionic)
2) gasoline No, nonnpolar
3) I2 No, nonpolar
4) HCl Yes, Polar
ColloidsColloids
Have medium size particles
Cannot be filtered
Separated with semipermeable membranes
Scatter light
(Tyndall effect)
Examples of ColloidsExamples of Colloids
Fog
Whipped
cream
Milk
Cheese
Blood plasma
Pearls
SuspensionsSuspensions
Have very large particles
Settle out
Can be filtered
Must stir to stay suspended
Examples of SuspensionsExamples of Suspensions
Blood platelets
Muddy water
Rate of Solution - SolidsRate of Solution - Solids
Solids dissolve faster (have greater solubility) with...Solids dissolve faster (have greater solubility) with...
• more stirring
• small particle size(increased surface area)
• high temperature
Temperature and Solubility of SolidsTemperature and Solubility of Solids
Temperature Solubility (g/100 g H2O) KCl(s) NaNO3(s)
0° 27.6 74 20°C 34.0 88 50°C 42.6 114100°C 57.6 182
The solubility of most solids (decreases or increases ) with an increase in the temperature.
Temperature and Solubility of SolidsTemperature and Solubility of Solids
Temperature Solubility (g/100 g H2O)
KCl(s) NaNO3(s)
0° 27.6 74
20°C 34.0 88
50°C 42.6 114
100°C 57.6 182
The solubility of most solids increases with an increase in the temperature.
Rate of Solution - GasesRate of Solution - Gases
Gases dissolve faster and have great Gases dissolve faster and have great solubility if...solubility if...
• no shaking or stirring
• high pressure above surface
• low temperature
Temperature and Solubility of GasesTemperature and Solubility of Gases
Temperature Solubility (g/100 g H2O)
CO2(g) O2(g)
0°C 0.34 0.0070 20°C 0.17 0.0043 50°C 0.076 0.0026
The solubility of gases (decreases or increases) with an increase in temperature.
Temperature and Solubility of GasesTemperature and Solubility of Gases
Temperature Solubility(g/100 g H2O)
CO2(g) O2(g)
0°C 0.34 0.0070
20°C 0.17 0.0043
50°C 0.076 0.0026
The solubility of gases decreases with an increase in temperature.
ConcentrationConcentration
Concentrated solutionConcentrated solution • large amount of solute
Dilute solutionDilute solution • small amount of solute
ConcentrationConcentration
% by Volume% by Volume: usu. liquid in liquid• EX: 10% juice = 10mL juice + 90mL
water
% by Mass% by Mass: usu. solid in liquid• EX: 20% NaCl = 20g NaCl + 80g water• % solution = mass of solute x 100
mass of solution
ConcentrationConcentration
SATURATED SOLUTION
no more solute dissolves
UNSATURATED SOLUTIONmore solute dissolves
SUPERSATURATED SOLUTION
becomes unstable, crystals form
concentration
SolubilitySolubility
SolubilitySolubility• maximum grams of solute that will
dissolve in 100 g of solvent at a given temperature
• varies with temperature• based on a saturated solution
g of solute 100 g water
Learning Check S1Learning Check S1
At 40C, the solubility of KBr is 80 g/100 g H2O.
Indicate if the following solutions are
(1) saturated or (2) unsaturated
A. ___60 g KBr in 100 g of water at 40C
B. ___200 g KBr in 200 g of water at 40C
C. ___25 KBr in 50 g of water at 40C
Solution S1Solution S1
At 40C, the solubility of KBr is 80 g/100 g H2O.
Indicate if the following solutions are
(1) saturated or (2) unsaturated
A. 2 Less than 80 g/100 g H2O
B. 1 Same as 100 g KBr in 100 g of water
at 40C, which is greater than its solubility
C. 2 Same as 60 g KBr in 100 g of water,
which is less than its solubility