CONJUGATE ACID-BASE PAIRS
Name________________________
Date__________________Per.____
In the exercise, Bronsted-Lowry Acids and Bases. it was shown that after an acid has given
up its proton, It is capable of getting back that proton and acting as a base.
Conjugate base is what is left after an acid gives up a proton.
 The stronger the acid, the weaker the conjugate base.
 The weaker the acid, the stronger the conjugate base.
Fill in the blanks in the table below.
CONJUGATE PAIRS
1.
2.
3.
Acid
Conjugate Base
H2SO4
HSO4-
(Sulfuric Acid)
HsSO4 ↔ H+ + HSO4Arrow (goes either way)
H3PO4
HF
FAdd H+
NO3-
4.
5.
H2PO4-
6.
H2O
SO4-2
7.
8.
HPO4+
9.
HN4-
10.
Gives away 1 H+
Equation
H2O
HF ↔ H+ + F-
(F with –1 remains)
Name _____________________
Date _____________Per ______
BRONSTED - LOWRY
ACIDS AND BASES
According to Bronsted-Lowry theory, an acid is a proton (H+) donor, and a base is a proton
acceptor.
H+
Example:
HCI + OH- → Cl- + H2O
Acid  give away H+
The HCI acts as an acid, the OH as a base
H2O (acid)
This reaction is reversible in that the H2O
Cl- (base)
can give back the proton to the Cl
Label the Bronsted-Lowry acids and bases in the following reactions and show the direction of
proton transfer.
H+
H-
H2O gave H(Acid)
+
Cl picks up H (Base)
[now conjugate Acid]
Example: H2O + Cl- ↔ OH- + HCl
Acid
Base
C. Base C. Acid
1. H20 + H20
Acid
↔
Base
H3O+
C. Acid
+ OHC. Base
2.
H2S04 + OH-
↔ HSO4 - + H2O+
3.
HSO4 - + H2O
↔ SO4-2 + H3O+
4.
OH- + H3O+
↔
H2O + H20
5.
NH3 + H2O
↔
NH4+ + OH-