Acids and Bases: The Final
Countdown
Shireen Rudina
Arrhenius Theory
In water, acids dissociate to form
H+ and bases dissociate to form
OHHCl H+ + H2O
Ba(OH)2 Ba+2 + 2OHNeutralization reaction:
Acid + Base => Salt + Water
HA + BOH  BA + H2O
Bronsted-Lowry Theory
Acids = H+ donors
Bases= H+ acceptors
NH3 + H2O  NH4+
so NH3 is a base
Every acid-base reaction
has a conjugate acid
and base
Label the acid/base, and conjugate
acid/base
HNO3 + H2O  H3O+ + NO3-
Acid + Carbonate  Salt + H2O + CO2
Egg:
CH3COOH + CaCO3  Ca(CH3COO) + H2O
+ CO2
Baking Soda & Vinegar:
CH3COOH + NaHCO3 
CH3COONa + H2O + CO2
Buffers
• Weak acid and its conjugate base
• Keep the pH around pKa of the acid
• Has a buffering capacity
Round 1: Multiple Choice
Questions are worth 10 points
What is true of a strong acid?
A. Has a Ka < 1
B. It can have a strong conjugate base
C. Can be neutralized by a strong base to form a
salt
D. It has a pH close to 5
Which of the following is NOT a strong
acid?
A. H2SO4
B. HI
C. HF
D. HNO3
E. HBr
Which of the following is NOT a strong
base?
A. KOH
B. LiOH
C. Ba(OH)2
D. BOH
The conjugate acid of a weak base can
be:
A. Only a strong acid
B. Only a weak acid
C. Either a strong or weak acid
A weak base:
A. Is very dilute
B. Dissociates a lot in water
C. Dissociates a little in water
D. Does not react with an acid
I want to make a buffer at pH=9.
Which conjugate acid-base pair could I
use?
Acid
pKa
Base
A
CH3COOH
4.8
CH3COONa
B
NH3
9.2
NH4+
C
C6H5OH
9.9
C6H5OH-
D
H2O
15
OH-
Round 2: Short Answer
20 points
What is the one molecule that
can be an acid or a base?
EXTRA +10 for the word that
describes molecules that can be acids
or bases (Italian is fine)
Write the equation for Ka
If I put .7 M of HCl in water, what is
[H+]?
If I put .5 M of the strong base
Ca(OH)2 in water, how many moles
of OH will I have?
What is the conjugate acid of
HSO4-?
Write out an example of a
neutralization reaction