Solutions/Acid & Bases
Chapter 15 & 19
• Solution are homogenous mixtures.
• Solutions are made up of 2 things:
– A solute & a solvent.
• Water is the most common solvent in
liquid solutions.
Soluble & Insoluble
• Dissolves in a solvent
• Example:
– Sugar in water
• Will not dissolve in a
solvent
• Example:
– Sand is insoluble in
water.
Miscible & Immiscible
• Two liquids that are
• Two liquids not
soluble in one another
soluble in one another
• Example:
• Example:
– Antifreeze & water
– Acetic acid & water
– Oil & vinegar
– Oil & water
Solute & Solvent
• What gets dissolved.
• The lesser amount of
substance in a
solution.
• Example:
– Sugar
– Salt
• What things dissolve
in.
• The greater amount
of substance in a
solution.
• Example:
– Water
– Ethanol
Solvation
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•
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Rules:
Like dissolves like.
Polar dissolves polar.
Nonpolar dissolves nonpolar.
Solvation of salt cont…
• Formula units break apart & ions become
attracted to charges of the water
molecules.
Solvation of salt
Solvation of sugar (covalent)
• In polar molecules, water molecules have
a stronger attraction to the polar molecules
than they have to each other.
“What can affect solubility?”
Two factors that affect rates of solutions.
1. Temperature
2. Pressure
Solvation & Crystallization
• Surrounding solute
particles with solvent
particles.
• Breaking apart.
• “Dissolving”
• Hydration
• Particles coming
together.
• Dehydration
Saturated & Unsaturated
• Max amount of solute
dissolves in a solvent
at a temp/pres.
• Ex:
– Concentrated or
strong tea
• Less solute is
dissolved than
saturated.
• It can dissolve more.
• Ex:
– Diluted or weak tea
Factors that affect solubility
1. Temperature:
• For solids- ↑ temperature, ↑ solubility
• For gases- ↑ temperature, ↓ solubility
2. Pressure:
• For gases in liquid- ↑ pressure, ↑ solubilty
• Super saturated solution- a solution that
contains more solute than saturated
solutions at the same temp/pressure
• http://www.youtube.com/watch?v=D1PDE
5OawuI&edufilter=iaYy5cltW5JHB2qLmdd
DPg
• Henry’s Law- at a given temperature,
solubility of a gas in a liquid is directly
proportional to the pressure of a gas
above the liquid.
• Example: a soda
15.2 Solution Concentration
• How much solute is dissolved in a specific
amount of solvent is concentration
Describing concentration
• Qualitative:
• Concentrated or diluted
Describing concentration
•
1.
2.
3.
4.
Quantitative:
Percent by volume
Molarity (M)
Molality
Normality
• Molarity: (M)(mol/L)=
moles of solute
liters of solution
Example 1
• A 100.5 mL intravenous solution contains
5.10 g of glucose (C6H12O6). What is the
molarity of this solution?
– Hint: glucose molar mass is 180. g/mol.
• Practice 1-3
15-3
Colligative Properties of
Solutions
• Physical properties that are affected by the
number of particles and not by their
identity are colligative properties.
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•
•
•
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Examples of colligative properties include:
1. vapor pressure lower
2. boiling point elevation
3. freezing point depression
4. osmotic pressure
• Solutions:
– Solutes will not settle out
– Will not scatter light
– Cannot filter
15-4 Heterogeneous Mixtures
• Suspensions:
– Settles out
– Scatters light
– Can be separated by filtering
– Are large particles (>1000 nm)
• Examples: muddy water, fine sand in
water
• Colloids:
– Don’t settle out
– Scatters light
– Can’t be filtered
– Medium to small sizes (<1000 nm)
– Examples: milk
• Brownian motion is the random movement
of colloid particles.
• Causes collision of particles preventing
them from settling.
• Tyndall effect:
– Particles scatter light
– Can be seen in suspensions & colloids
• Examples: ray of light through fog or
smoke
Acid & Bases
Chapter 19
• Acids, bases, & salts are electrolytes
because they conduct electrical current.
• An indicator is a compound that changes
color to indicate the presences of an acid
or base.
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•
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Characteristics of acids
Sour taste
Reacts with metals
Neutralizes bases
affects indicators
– turns blue litmus red/pink
– keeps phenolphthalein colorless
– turns methyl orange red
Common Acids:
• Citric acid- in citrus fruits
– (Lemons, oranges, etc)
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•
•
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Acetic acid- vinegar
Malic acid- apple
Butyric acid- sour butter
Lactic acid- sour milk; builds up in muscles
during exercise.
Industrial acids:
• Sulfuric acid- (H2SO4) most manufactored
chemical in US; fertilizers
• Phosphoric acid- (H3PO4) fertilizers;
detergents
• Nitric acid- (HNO3) fertilizers; explosives
• Hydrochloric acid- (HCl) used to “pickle”
steel (remove surface impurities)
Review: Naming acids
• 1. Binary acids- (only 2 elements)
“hydro________ic acid”
– Ex. HBr
– Ex. H2S
• 2. Oxyacids- (has polyatomic ions)
“________ic acid”
– Ex. HClO3
– Ex. H2SO4
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Characteristics of Bases
tastes bitter
feels slimy
affects indicators
– pink litmus turns blues
– phenolphthalein turns bright pink
– methyl orange turns yellow
Common Bases:
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•
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Ammonia- (NH3) cleaning agent
Lye- (NaOH) draino
Milk of magnesia- (Mg(OH)2) laxative
Lime- (Ca(OH)2) mortar for bricks, foul
lines on fields
• What is pH?
• pH is the negative logarithm of H+1 ion
concentration
• pH= -log[H+]
• pH range- 014
• pH scale: acids  0-6.99, neutral  7,
base  7.01-14
Example 2
• What is the pH of a solution with the
concentration [H+]= 1.0 x 10-7 M?
• Practice
4. What is the pH of [H+]=1.0x10-2?
5. What is the pH of [H+]=3.0x10-6?
pOH?
6. What is the pOH of [OH-]=8.2x10-6?
• Ex. 3 What is the concentration (Molarity)
of H+ of an acidic solution with the pH of
3.20?
• Practice:
• 7. Calculate the concentration of H+ of an
acidic solution with the pH of 6.55.
Neutralization
• Neutralization Reaction- reaction between an
acid & base to produce a salt & water
• Salt- made of the positive ion (from base) & the
negative ion (from acid)
• Example:
• Mg(OH)2 + HCl 
• Practice:
• H3PO4 + Ca(OH)2 
• Al(OH)3 + H2SO4 
Arrhenius vs Bronted-Lowry
• Acid is the sub.
containing H
• Base is the sub.
containing OH
• Ex. HCl & NaOH
• Acid is the sub. that
loses the H+
• Base is the sub. that
gains the H+.
• involves conj. acid &
bases
H2O + NH4+  NH3 + H3O+
• Practice:
• Identify the following Bronsted-Lowry acids
& bases.
• HC2H3O2 +H2O  H3O+ + C2H3O2-
• Anhydrides are compounds that can
become acids or bases when water is
added.
• Ex. Which is the anhydride?
– CO2 + H2O  H2CO3
• Practice. Which is the anhydride?
– CaO + H2O Ca(OH)2
– H2O + SO2  H2SO4