Schedule
Acids & Base Schedule for Yellow Fellows
Today
18.1 & 18.2
Wednesday
18.3
Thursday
18.4
Identify acids & bases
Strong Acids & Bases
Naming
Concentration (pH & pOH)
Molarity
Neutralization
Buffers
Titration
Wednesday
Review
Thursday
Quiz
Schedule
Acids & Bases Schedule Team Tree
Today
18.1 & 18.2
Wednesday
18.3
Double Lab
18.4
Identify acids & bases
Strong Acids & Bases
Naming
Concentration (pH & pOH)
Molarity
Neutralization
Buffers
Titration
Wednesday
Review
Friday
Quiz
Unilever’s Bread & Butter
The Chemistry of Love…
• Initial attraction through nonverbal communication is often
attributed to phermones.
• “Raw lust” is characterized by high levels of testosterone?
• The sweaty palms and pounding heart of infatuation are
caused by higher than normal levels of norepinepherine.
• The 'high' of being in love is due to a rush of
phenylethylamine and dopamine.
• Lasting love confers chemical benefits in the form of stabilized
production of serotonin and oxytocin.
• Can infidelity be blamed on chemistry? Perhaps in part.
Researchers have found that suppression of vasopressin can
cause males (voles, anyway) to abandon their love nest and
seek new mates.
A delicious acid
Schedule
Acids & Bases Schedule for Lava Lovers
Tuesday (2/14)
18.1 & 18.2
Wednesday (2/15)
Identify acids & bases
Strong Acids & Bases
Naming
18.3
Concentration (pH & pOH)
Molarity
18.4
Neutralization
Buffers
Wednesday (2/22)
Friday Double Lab (2/23)
18.4
Titration Lab
Quiz
Today’s Objective – 18.1 & 18.2
• To identify acids and bases using the
Arrhenius, Brønsted-Lowry and Lewis models.
• To identify strong & weak acids and bases.
• To name acids & bases.
• Tonight’s homework:
– read section 18.3 & take notes
– mini quiz tomorrow
Content: What is an Acid?
• Arrhenius model: A species that contains
hydrogen and produces hydrogen ions in an
aqueous (water) solution.
HX  H+ + X– Real example:
HCl  H+ + Cl-
Content: What is an Acid?
• Brønsted-Lowry model: hydrogen ion donor.
Produce conjugate acids and bases
HX(aq) + H2O  H3O+(aq) + X-(aq)
–Real example:
HF(aq) + H2O  H3O+(aq) + F-(aq)
Content: conjugate acids and bases
acid
base
conjugate
acid
conjugate
base
• conjugate acid: the species produced when a
base accepts a hydrogen ion.
• conjugate base: the species that results when
an acid donates its hydrogen ion.
Content: What is a base?
• Arrhenius model: species that produces
hydroxide ions in an aqueous solution.
MOH  M+ + OH– Real examples:
NaOH  Na+ + OH-
Content: What is a base?
• Bronsted-Lowry model: hydrogen ion
acceptor.
NH3(aq) + H2O(l)  NH4+(aq) + OH-(aq)
base
acid
conjugate
acid
conjugate
base
Content: Water – both acid & base
H 2 O + H2 O 
• Known as: amphoteric
• Complete the equations. In each, is water an acid
or base?
– HX + H2O 
– NH3 + H2O 
Summarize: Compare & Contrast
3 words or less
Model
Arrhenius
Brønsted-Lowry
Acid Definition
Base Definition
Summarize: Make Connections
• What real world substances are classified as
acids and bases?
• What ion is likely present in acids?
Today’s Objective – 18.2 & 18.3
• To classify strong acids and bases v. weak acids
& bases.
• To explain pH and pOH.
• Tonight’s homework:
– worksheet if you don’t finish it in class.
Content: Strong Acids and Bases
• Strong: completely ionizes in aqueous solutions
– Strong acid equation
• HX (aq) 
– Strong base equation
• MOH 
Strong Acids & Bases
Memorize
Acids
• HCl
• HBr
• HI
• HNO3
• H2SO4
• HClO4
Bases
• Hydroxides of group 1 or 2
metals
– Ex: NaOH, KOH, Mg(OH)2
Content: Weak acids & bases
• Only partially dissociate in water. Reaction
does not go to completion, is reversible.
• Use double arrow
– Weak acid reaction
• HB (aq)
– Weak base reaction
• NH3(aq) + H2O
What does this look like?
• http://phet.colorado.edu/en/simulation/acidbase-solutions
Check for Understanding
• Classify the following as weak/strong
acid/base.
– HF
– LiOH
– HBr
– NaOH
– NH3
Check for Understanding
• What would happen to the following
substances in water? Write an equation for
each and draw what this would look like
– HF
-LiOH
– NaOH
-NH3
– HBr
Classification of acids and Bases
• If [H+] > [OH-] =
• If [OH-] > [H+] =
• If [H+] = [OH-] =
Today’s Objective
• To understand pH.
• To neutralize an acid using titration.
18.3 Ion Product Constant for Water
• Pure water contains equal concentrations of H+
and OH– ions.
• The ion production of water
Kw = [H+][OH–] = 1.0x10-14
• a number that doesn’t change, a constant number.
• equals the concentration of the H+ and OH– ions.
Ion Product Constant for Water
• In an acidic or basic solution, as the [H+] goes up,
[OH-] goes down, and vice versa so Kw remains
the same.
The pH scale
• Scientific notation is cumbersome, so it’s re-expressed
using logs.
• pH is the negative logarithm of the hydrogen ion
concentration of a solution.
pH = –log [H+]
Did she just say “log?!”
• 103 = 1000
o 10 is the base.
o 3 is the exponent.
• A logarithm is basically solving for exponents, x in the
following
o 10x=1000
o here x = 3
• log101000 = x
• log101000 = 3
• "The log of 1000, base 10, is 3”
logbase(number) = exponent
So for pH…
• If [H+] = 1.0 x 10-7
• and pH = - log [H+]
• then pH = - log [1.0 x 10-7] = - (-7) log 10
• and pH = 7 x 1 = 7
• so this would be a neutral solution.
The pOH scale
• pOH is the negative logarithm of the hydroxide
ion concentration of a solution.
pH = –log [OH-]
pH + pOH = 14
Concentration of Strong Acids &
Bases
For all strong monoprotic acids (ones that have one H+
ion to donate) the concentration of the acid is the
concentration of H+ ions.
For all strong bases, the concentration of the OH– ions
is the concentration of the base.
A 0.6M solution of NaOH means there are 0.6 moles
of NaOH per liter of water.
NaOH  Na+ + OHFor every mole of NaOH, there is one mole of OH-, so
the concentration is the same.
Neutralization
• What happens if we mix a strong acid and a
strong base?
• A neutralization reaction is a reaction in which
an acid and a base in an aqueous solution react
to produce a salt and water.
• The net reaction (without the salt) is:
Titration
• It’s all in the technique…
Titration
• Titration is a method for determining the concentration of
a solution by reacting a known volume of that solution
with a solution of known concentration.
HCl + NaOH  NaCl + H2O
• If I have 50 mL of a 0.5M solution of HCl, how much of a
0.5M solution of NaOH should be needed to neutralize it?
How can we use this to determine the concentration of an
unknown acid or base?
Titration Procedure
• In a titration procedure, a measured volume of an acid
or base of unknown concentration is placed in a
beaker, and initial pH recorded.
Titration Procedure
• A buret is filled with the titrating solution of known
concentration, called a titrant.
Titration Procedure
• Measured volumes of the titrant are added slowly
and mixed into the solution in the beaker.
• The pH is read and recorded after each addition.
pH indicator solution
• Chemical dyes whose color are affected by acidic and
basic solutions are called acid-base indicators.
• An end point is the point at which an indicator used in a
titration changes color.
• An indicator will change color at the equivalence point.
End Point
• The process continues until
the reaction reaches the
equivalence point, which is
the point at which moles of
H+ ions from the acid equals
moles of OH– ions from the
base.
• An abrupt change in pH
occurs at the equivalence
point.
Expected Titration Curve
Let’s Practice
Naming Bases
• Bases
– Group 1 and 2 hydroxides…
– NH3 (ammonia)
Naming Acids
• Binary Acids (hydrogen + 1 element)
– Prefix “Hydro” to name the hydrogen part of the
compound
– The rest of the word consists of a form of the root
of the second element, plus the suffix “ic”
– Second word is always “acid”
•
•
•
•
Example: HCl  Hydrochloric Acid
Example: HF  Hydrofluoric Acid
Example: HI 
Example: HBr 
Naming Acids
• Oxyacids (contain hydrogen and oxyanion)
– Identify oxyanion. The first word is the oxyanion
name and a suffix
• If original suffix was “ate”  “ic”
• If original suffix was “ite”  “ous”
– Second word = “acid”
•
•
•
•
•
•
Example: HClO4 = Perchloric Acid
Example: HClO3= Chloric Acid
Example: HClO2 =
Example: HClO=
(adds chlorine to pools)
Example: HNO3
Example: HNO2
In Conclusion
• Using the pH scale, identify what makes a
substances acidic, basic or neutral
• What is more dangerous, an acid or a base?
• What ion is responsible for an acidic solution?
A basic solution?
• Name the following acids
•
•
•
•
•
H2SO4
H2SO3
HCl
HF
H2CO3