PORTAGE BIOCHEMISTRY - MODULE 2
EXAM
1. The pH of a solution of 0.0010 M NaOH is
A. 1
B. 11
C. 8
D. 0
E. 14
Answer B. 11
1.0 x 10^-14 = [H+][OH-]
1.0 x 10^-14 = [H+][0.0010]
1.0 x 10^-14 /0.0010
1.0 x 10^-11 = H+
pH = -log[1.0 x 10^-11] = 11
2. The pH of a solution of 8.9 x 10-12M NaOH is
,A. 8.9
B. 8.9 x 10^-12
C. 4.8
D. 11
E. 2.9
Answer E. 2.9
Kw=[H+][OH-]
1.0 x 10^-14= [H+][8.9 x 10^-12]
[H+]=890
pH=-log[890]
2.9
3. The pH of a solution of 3.2 x 10^-10 M NaOH is
A. 3.7
B. 3.7 x 10^-10
C. 4.5
,D. 13
E. 8.7
Answer C. 4.5
, 1.0 x 10^-14 = [H+][OH-]
1.0 x 10^-14 = [H+][3.2 x 10^-10]
1.0 x 10^-14/3.2 x 10^-10 = [H+]
3.25 x 10^-5 = [H+]
pH = -log [H+]
pH = -log [3.25 x 10^-5]
pH = 4.5
4. Water is a unique molecule. Which of the following contributes to water's
unique place in the chemical world?
A. The geometry of the molecule
B. The polarity of the O-H bonds
C. The ability of water molecules to hydrogen bond
D. The bond angle of water
EXAM
1. The pH of a solution of 0.0010 M NaOH is
A. 1
B. 11
C. 8
D. 0
E. 14
Answer B. 11
1.0 x 10^-14 = [H+][OH-]
1.0 x 10^-14 = [H+][0.0010]
1.0 x 10^-14 /0.0010
1.0 x 10^-11 = H+
pH = -log[1.0 x 10^-11] = 11
2. The pH of a solution of 8.9 x 10-12M NaOH is
,A. 8.9
B. 8.9 x 10^-12
C. 4.8
D. 11
E. 2.9
Answer E. 2.9
Kw=[H+][OH-]
1.0 x 10^-14= [H+][8.9 x 10^-12]
[H+]=890
pH=-log[890]
2.9
3. The pH of a solution of 3.2 x 10^-10 M NaOH is
A. 3.7
B. 3.7 x 10^-10
C. 4.5
,D. 13
E. 8.7
Answer C. 4.5
, 1.0 x 10^-14 = [H+][OH-]
1.0 x 10^-14 = [H+][3.2 x 10^-10]
1.0 x 10^-14/3.2 x 10^-10 = [H+]
3.25 x 10^-5 = [H+]
pH = -log [H+]
pH = -log [3.25 x 10^-5]
pH = 4.5
4. Water is a unique molecule. Which of the following contributes to water's
unique place in the chemical world?
A. The geometry of the molecule
B. The polarity of the O-H bonds
C. The ability of water molecules to hydrogen bond
D. The bond angle of water
