Acids and Bases
Chapter 14 – One step closer to
the AP Test
Arrhenius Definition
Acids
produce hydrogen ions in aqueous solution.
Bases
produce hydroxide ions when dissolved in
water.
Limits
Only
NH3
to aqueous solutions.
one kind of base.
ammonia could not be an Arrhenius base.
Bronsted-Lowry
Definitions




And acid is an proton (H+) donor and a base
is a proton acceptor.
Acids and bases always come in pairs.
HCl is an acid.
When it dissolves in water it gives its proton
to water.
H+ + Cl-

HCl(g)

Water is a base -makes hydronium ion
What do all of these
have in common?
NH3
H 2O
CO32-
Dissociate the Following
1. Hydrochloric acid
2. Acetic acid
3. Ammonium ion
4. Anilinium ion (C6H5NH3+)
5. Hydrate Aluminum (III) ion [Al(H2O)6]3+
1. HCl
2. HC2H3O2
3. NH4+
4. C6H5NH3+
5. [Al(H2O)6]3+
H+ + ClH+ + C2H3O2H+ + NH3
H+ + C6H5NH2
H+ + Al(H2O)5OH2+
Polyprotic Acid
Be careful dissociating polyprotic acids.
H2SO4
H+ + HSO4- SA
HSO4H+ + SO42- WA
H3PO4
H+ + H2PO4-
WA
Pairs
General equation
 HA(aq) + H2O(l)
H3O+(aq) + A-(aq)
 Acid + Base
Conjugate acid +
Conjugate base
 This is an equilibrium.
+
 Competition for H between H2O and A
 The stronger base controls direction.
+
 If H2O is a stronger base it takes the H
 Equilibrium moves to right.

Writing Net Ionic A-B
Reactions
1- Determine if the species are an acid, base or salt
2 – Determine if the acid or base are strong or weak
If SA or SB dissociate completely (Show with an
)
If WA or WB it reaches equilibrium (Show with an
)
3. If a salt, determine if either ion is reactive (Comes from a WA or
WB)
Determine whether the reactive ion acts as an acid or base
(What type of solution is it in)
Write the reaction of the ion.
4. Write the neutralizations reaction
5. Cross out SA, SB and Salt reactions
6. Add the remaining reactions together
Let’s try one together
Equimolar amounts of hydrochloric acid
and potassium hydroxide are mixed.
HCl
H+ + ClSA
KOH
K+ + OHSB
H+ + OHH 2O
H+ + OH-
H 2O
Another example
0.1M nitrous acid solution is added to the same
volume of a 0.1M sodium hydroxide solution.
(Equimolar amounts = H2O MUST be a product)
HNO2
H+ + NO2NaOH
Na+ + OHH+ + OHH2O
HNO2 + OH-
wa
sb
H2O +
NO2-
Example #2
A solution of potassium hydroxide is added to a
solution of ammonium chloride.
KOH
K+ + OHSB
NH4Cl
NH4+ + Cl- salt
NH4+
NH3 + H+
H+ + OHH2O

NH4+ + OH-
NH3 + H2O
Example #3
Dilute acetic acid solution is added to solid
magnesium carbonate.
HC2H3O2
MgCO3
CO32- + H2O
H+ + OHHC2H3O2 + CO32-
H+ + C2H3O2wa
Mg2+ + CO32- salt
HCO3- + OHH2O
HCO3- + C2H3O2-
And yet another
one…from the WS
Solutions of ammonia and hydrofluoric acid are mixed.
NH3 + H2O
NH4+ + OHHF
H+ + F- wa
H+ + OHH2O
NH3 + HF
NH4+ + F-
wb
Problem #2
Hydrogen sulfide has is bubbled through a solution of
potassium hydroxide.
H2S
H+ + HSKOH
K+ + OHH+ + OHH2O
H2S + OH-
wa
sb
H2O + HS-
Problem #3 – A twist
A solution of sulfuric acid is added to a solution of
barium hydroxide until the same number of moles
of each compound has been added.
H2SO4
Ba(OH)2
H+ + OH-
H+ + HSO4Ba2+ + 2OHH2O
Ba2+ + SO42- + H+ + OH-
sa
sb
H2O + BaSO4
Problem #4
A solution of sodium hydroxide is added to a solution
of sodium dihydrogen phosphate until the same
number of moles of each compound has been
added.
NaOH
Na+ + OHsb
NaH2PO4
Na+ + H2PO4H2PO4H+ + HPO42H+ + OHH2O
H2PO4- + OH-
H2O + HPO42-
salt
Problem #5
Dilute nitric acid is added to crystals of pure calcium
oxide.
HNO3
H+ + NO3- sa
CaO + H2O
Ca2+ + 2OH2H+ + 2OH2H2O
CaO + 2H+
Ca2+ + H2O
Jump to Problem #8
Excess sulfur dioxide gas is bubbles through a dilute
solution of potassium hydroxide.
KOH
K+ + OHSO2 (NMO + H O)
HSO3HSO3H+ + SO32H+ + OHH2O
sb
2
SO2 + OH-
H2O + SO32-