Transcript Solute Solvent Example

Unit 13 - Solutions
Solution – a homogeneous mixture of two or
more substances
Solvent: dissolving medium Ex: water
Solute: substance that dissolves Ex: sugar,
salts
Classification of Mixtures: true solution,
suspension, and colloids
1.
True solution: when a solute is dispersed
throughout a solvent and form a
homogeneous mixture (single phase)
Ex: sugar+water; salt + water
2. Suspension: particles of a solute are huge
compared to molecules of a solvent and
form a heterogeneous mixture. Ex: muddy
water, orange juice (filtration)
3. Colloids: particles are suspended through
out the solvent. It may appear to be
homogeneous, but examination (tyndall
effect) shows that they are not a true
solution.
Ex: mayonnaise (emulsion), milk, butter,
gelatin, whipped cream, fog. smoke, mist,
paints, glue.
Tyndall Effect: distinguish true solution and
colloid by passing a beam of light.
Emulsion: liquid suspended in a liquid.
Unit 13 - Solutions
SUSPENSION
COLLOID
SOLUTIONS
Completely Settle Out
Do not Settle Out
Do not Settle Out
Pass Changed
(Separated)
Pass Unchanged
Through Filter Paper
Pass Unchanged
Through Filter Paper
Separated by
Membranes
Separated by
by Membranes
Not separated by
by Membranes
Scatter Light
Scatter Light
Not Scatter Light
Not Affect Colligative
Property
Affect Colligative
Properties
Not Affect Colligative
Property
> 100 nm
100 nm – 10 nm
< 10 nm
1. Brownian Motion: Continuous motion of
colloidal properties, random
2. Tyndall Effect: Light scattering by colloidal
particles. “ Like dissolves Like.”
Definition:Substances with similar bonding are
mutually soluble – Miscible
Examples
1. HOH with Alcohol
Polar/ Polar
2. HOH with Glycerol
Polar/ Polar
3. HOH with salt
Polar/ Ionic
4. Oil with gasoline
Covalent/ Covalent
1.
2.
3.
4.
Aqueous = HOH based
Gaseous = Gas based
Other = Liquid/Solid/ Gas
Alloys= Metals- 2 or more (melt the solidify)
SOLVENT- The dissolving medium-large
mass/volume
SOLUTE - The substance be dissolved- small
mass/volume
Types of Solutes:
1. Electrolytes: conduct electric current.
Ex: salt water
2. Nonelectrolytes: non conduct electric
current. Ex: sugar water
Factors affecting the rate of dissolution:
1. Increasing the surface area of the solute
2. Agitating a solution
3. Heating a solution
Solubility: the amount of solute is dissolved
by a solvent at a given temperature.
Unsaturated solution: more solute can be
dissolved.
Saturated solution: the maximum amount of
dissolved solute in a solution
Supersaturated solution: a solution that has
more dissolved solute than a saturated
solution at the same conditions.
Types of Solutions:
Solute Solvent Example
gas
gas
deep sea gas (He in O2)
gas
liquid
soda (CO2 in water)
gas
solid stove lighter (H2 in platinum)
liquid
gas
water vapor in air
liquid
liquid
antifreeze in water
liquid
solid Hg in Sn/Ag-dental amalgam
S
Solids
Alloy
(Jewelry Ag
& Au)
Liquids
Dental
Amalgam
(Silver/ Hg)
2
Salt Water
L
(HOH/NaCl)
Vinegar
(Acetic
Acid/HOH)
3
Air
Naphthalene
(Moth Balls)
1
G
Humidity
(Air/ HOH)
Gases
Gas Stove
Lighter
(Pd/H2 )
Carbonate
Beer
(HOH/CO2)
Deep Sea
Gas
(He/O2)
1.
2.
3.
Solvent-Solvent
(Hydration)
Solute-Solute
Solvent-Solute
Dissociation ( Solvation)
Dissociation
Association
H +,--,0
Rate of Dissolving
1. Heat Solvent
2. Powder Solute
3. Stirring Solution (Agitate)
4. Adjust Volume of Solvent v. Solute
Factors
1
LDL
S/S
Melt
2
S/L
3
S/G
LDL
Temperature
Limits
No
No
No
No
Melt
LDL
Adsorbs/
Absorbs
Pressure
No
Surface
Area of
Solid
Factors
Temperature
Limits
LDL
Yes
L/S
Powder
Agitate
T,
Solubility
2
LDL
No
No
LDL
Pressure
Henry’s Law
Yes
Yes
1
Yes
L/L
3
L/G
T,
Solubility
Factors
1
G/S
2
G/L
3
G/G
Temperature
Limits
No
Yes
Volume
of Gas
Nature of
Solute
Gravity
Yes
Yes
Pressure
Availability
of Solute
Solubility
Temp. &
Volume
No
No
No
T,
Henry’s Law: Solubility of a gas in a
liquid is directly proportional to the
partial pressure of that gas on the surface
of the liquid.
Solubility:the amount of solute is dissolved
by a solvent at a given temperature.
Saturation: Quantity of Solute per Volume (Mass)
Solvent
Unsaturated- holding less than max. under the
conditions
Saturated- Maximum Solute per Unit of Solvent
L/S
Temp. sensitive
L/G Temp. & Pressure Sensitive
Supersaturated- holding greater than Max. under
specific condition.
L/S
Heat, Add Solute, Cool
L/G Keep under pressure
Return to Saturation
1.
2.
3.
Addition of a seed crystal; Shock “ping”, agitate
Sudden Temp. Change Cooling
Sudden Reduction in Pressure (gases only)
DILUTE vs. COCENTRATED: Add solvent/
remove solvent
SOLUTION EQUILIBRIUM
Definition: Physical state in which opposing
processes of dissolving & crystallizing occur
at equal rate.
LeChatelier: Stress on a system causes a shift in
the equilibrium of a system
“Stress”: 1. T
2. P
3.Agitation
AT “0”C AT 20 C AT 40 C AT 60 C AT 80 C AT 100 C
1 Sugar
C12H22O11 179 g
204 g
238 g
287 g
362 g
487 g
35.7 g
36.0 g
36.6 g
37.3 g
38.4 g
39.8 g
1.54 g
1.33 g
1.17 g
1.01 g
.85 g
.72 g
2
NaCl
3
Li2 CO3
“+” curve
M
A
S
“0” Curve
S
“_” Curve
Temperature
Heat of a Solution: The difference between the
heat contents of a solution and the H of its
components.
Exothermic: Heating; - H ;KOH,NaOH
Endothermic: Cooling; + H; KNO3, AgNO3
Isothermic: No Change “Neutral”; zero H;
C2 H3OOH(1), NaCl