solutions. recall types of mixtures: suspensions colloids solutions all mixtures are physically...
TRANSCRIPT
SOLUTIONS
RECALL
TYPES OF MIXTURES:
SUSPENSIONSCOLLOIDS
SOLUTIONS
All mixtures are physically combined and can be physically separated.
DEFINITION
A solution is a homogeneous mixture of two or more substance in a single physical state
Parts of a solution
SOLUTE – the substance that is dissolvedSOLVENT- the substance that does the dissolving
Definitions
Solute Solute - KMnO4 Solvent Solvent - H2O
TYPES OF SOLUTIONS
SOLUTE SOLVENT EXAMPLEGAS GAS AirGAS LIQUID Seltzer (CO2)
LIQUID LIQUID Antifreeze (ethyl glycol in water)SOLID LIQUID Sea water ( salt in water)GAS SOLID Charcoal filter (poisonous gases in
carbon)LIQUID SOLID Dental filling (mercury in silver)SOLID SOLID Sterling silver (copper in silver)
SOLID SOLUTION
• Contain two or more metals called alloys• Formed by melting the components and
mixing them together and allowing them to cool
• Properties of alloys are different from the original component metals
TYPES OF ALLOYSALLOY COMPONENT USES
Babbitt Tin, antimony, copper Bearings
Bell metal Copper, tin Bells
Coinage metals Copper, tin, zinc Coins
16 karat gold Gold, copper, silver Jewelry
Sterling Silver, copper Jewelry, flatware
Nichrome Nickel, iron, chromium, manganese
Heating elements
GASEOUS SOLUTIONS
• All mixture of gases• Properties depend on the properties of its
componentsExample: Nitrogen in air serves as a gas that
dilutes pure oxygen which is toxic to people and animals, and is very combustible.
LIQUID SOLUTIONS• Most familiar type of solution• The solvent and the solution are liquids• Solute may be a gas, a solid, or a liquid• It is proper to describe liquids that are soluble
to each other as MISCIBLE or can mix. And insoluble liquids as IMMISCIBLE. Or cannot mix. Example: alcohol is miscible in water while oil is immiscible in water.
Important terminologies:
• Soluble – substance that dissolves another substance
• Insoluble – substance that does not dissolve another substance
• Miscible – liquids that are completely soluble in each other or can mix
• Immiscible – liquids that are not soluble in each other or cannot mix
AQUEOUS SOLUTIONS
• Solutions with water as the solvent• Aqueus, means like or containing water.• Substances that dissolve in water are
classified according to whether they produce ions or molecules in solution.
• Solutions that conduct electricity are called ELECTROLYTES.
SOLUBILITY
SolubilitySolubilitySolubility
maximum grams of solute that will dissolve in 100 g of solvent at a given temperatureg solute/100 mL H2O
varies with temp
based on a saturated solution
Solubility
SATURATED SOLUTION
no more solute dissolves
UNSATURATED SOLUTIONmore solute
dissolves
SUPERSATURATED SOLUTION
becomes unstable, crystals form
increasing concentration increasing concentration
Determine if a solution is saturated,unsaturated,or supersaturated.
• If the solubility for a given substance places it anywhere on it's solubility curve it is saturated.• If it lies above the solubility curve, then it's supersaturated,• If it lies below the solubility curve it's an unsaturated solution.
Temp. (oC)
Solubility(g/100 g H2O)
KNO3 (s)
KCl (s)
HCl (g)
SOLUBILITYCURVE
Solubility how much solute dissolves in a given amt.
of solvent at a given temp.
unsaturated: solution could hold more solute; belowbelow line
saturated: solution has “just right” amt. of solute; onon line
supersaturated: solution has “too much” solute dissolved in it;
above the line
To
Sol.
To
Sol.
Solids dissolved in liquids Gases dissolved in liquids
As To , solubility As To , solubility
Sometimes you'll need to determine how much additional solute needs to be added to a unsaturated solution in order to make it saturated.
For example,30 grams of potassium nitrate has been added to 100 cm3 of water at a temperature of 50ºC.
How many additional grams of solute must be added in order to make it saturated?
From the graph you can see that the solubility for potassium nitrate at 50ºC is 84 grams
If there are already 30 grams of solute in the solution, all you need to get to 84 grams is 54 more grams ( 84g-30g )
Solubility Table
LeMay Jr, Beall, Robblee, Brower, Chemistry Connections to Our Changing World , 1996, page 517
shows the dependence
of solubility on temperature
0 10 20 30 40 50 60 70 80 90 100
Solubility vs. Temperature for Solids
Sol
ubili
ty (
gram
s of
sol
ute/
100
g H
2O)
KI
KCl
20
10
30
40
50
60
70
80
90
110
120
130
140
100
NaNO3
KNO3
HCl NH4Cl
NH3
NaCl KClO3
SO2
gases
solids
Classify as unsaturated, saturated, or supersaturated.Classify as unsaturated, saturated, or supersaturated.
per100
gH2
O
80 g NaNO3 @ 30oC
45 g KCl @ 60oC
50 g NH3 @ 10oC
70 g NH4Cl @ 70oC
=unsaturated
=saturated
=unsaturated
=supersaturated
0 10 20 30 40 50 60 70 80 90 100
Solubility vs. Temperature for Solids
Sol
ubili
ty (
gram
s of
sol
ute/
100
g H
2O)
KI
KCl
20
10
30
40
50
60
70
80
90
110
120
130
140
100
NaNO3
KNO3
HCl NH4Cl
NH3
NaCl KClO3
SO2
gases
solids