Portage Learning – Biochemistry Module 2
50-Question Full-Length Mock Exam (75 minutes)
Instructions
•Time limit: 75 minutes
•Calculator allowed
•No notes
•Choose the best answer
Section I: Multiple Choice (1–40)
1. The bent geometry of water is primarily due to:
A. Hydrogen bonding
B. Unequal electronegativity
C. Lone pair–bonding pair repulsion
D. Covalent bond angles
2. Which property of water allows lakes to remain liquid beneath ice?
A. Adhesion
B. Cohesion
C. Density anomaly of ice
D. High vapor pressure
3. Which interaction stabilizes protein secondary structure?
A. Ionic bonds
B. Hydrogen bonds
C. Disulfide bonds
D. Peptide bonds
4. Which interaction is strongest?
A. London dispersion
B. Dipole–dipole
C. Hydrogen
bonding
D. Ionic attraction
5. Autoionization of water produces:
A. H■ and O²■
B. H■ and O■
C. H■O■ and OH■
D. H■O■ and H■
6. At 25°C, the value of Kw is:
A. 1 × 10■■
B. 1 × 10■¹■
C. 14
D. 1 × 10■¹
7. A solution has [H■] = 4.0 × 10■■ M. The pH is closest to:
A. 4.40
B. 5.40
C. 9.60
D. 10.40
, 8. A solution with pH 4 is how many times more acidic than pH 7?
A. 3×
B. 10×
C. 100×
D. 1000×
9. Which expression correctly represents Ka?
A. [HA]/[H■][A■]
B. [H■][A■]/[HA]
C. [H■]/[A■]
D. [A■]/[HA]
10.When pH = pKa:
A. Solution is neutral
B. Acid fully protonated
C. [A■] = [HA]
D. Buffer capacity is zero
11.A buffer is most effective when:
A. pH = 7
B. pH = pKa
C. pH > pKa by 3 units
D. pH < pKa by 3 units
12.Which is a conjugate acid-base pair?
A. HCl / NaCl
B. H■O / OH■
C. H■O / H■
D. H■O■ / H■
13.Increasing [A■] relative to [HA] will:
A. Decrease pH
B. Increase pH
C. Not affect pH
D. Destroy buffer
14.Which molecule can hydrogen bond with water?
A. CH■
B. CO■
C. NH■
D. O■
15.Which statement about buffers is correct?
A. Prevent pH change completely
B. Only work at pH 7
C. Resist changes in pH
D. Neutralize acids fully
Gibbs Free Energy Questions
16.Which condition results in a spontaneous reaction?
A. G > 0
B. G = 0
C. G < 0
D. H > 0
50-Question Full-Length Mock Exam (75 minutes)
Instructions
•Time limit: 75 minutes
•Calculator allowed
•No notes
•Choose the best answer
Section I: Multiple Choice (1–40)
1. The bent geometry of water is primarily due to:
A. Hydrogen bonding
B. Unequal electronegativity
C. Lone pair–bonding pair repulsion
D. Covalent bond angles
2. Which property of water allows lakes to remain liquid beneath ice?
A. Adhesion
B. Cohesion
C. Density anomaly of ice
D. High vapor pressure
3. Which interaction stabilizes protein secondary structure?
A. Ionic bonds
B. Hydrogen bonds
C. Disulfide bonds
D. Peptide bonds
4. Which interaction is strongest?
A. London dispersion
B. Dipole–dipole
C. Hydrogen
bonding
D. Ionic attraction
5. Autoionization of water produces:
A. H■ and O²■
B. H■ and O■
C. H■O■ and OH■
D. H■O■ and H■
6. At 25°C, the value of Kw is:
A. 1 × 10■■
B. 1 × 10■¹■
C. 14
D. 1 × 10■¹
7. A solution has [H■] = 4.0 × 10■■ M. The pH is closest to:
A. 4.40
B. 5.40
C. 9.60
D. 10.40
, 8. A solution with pH 4 is how many times more acidic than pH 7?
A. 3×
B. 10×
C. 100×
D. 1000×
9. Which expression correctly represents Ka?
A. [HA]/[H■][A■]
B. [H■][A■]/[HA]
C. [H■]/[A■]
D. [A■]/[HA]
10.When pH = pKa:
A. Solution is neutral
B. Acid fully protonated
C. [A■] = [HA]
D. Buffer capacity is zero
11.A buffer is most effective when:
A. pH = 7
B. pH = pKa
C. pH > pKa by 3 units
D. pH < pKa by 3 units
12.Which is a conjugate acid-base pair?
A. HCl / NaCl
B. H■O / OH■
C. H■O / H■
D. H■O■ / H■
13.Increasing [A■] relative to [HA] will:
A. Decrease pH
B. Increase pH
C. Not affect pH
D. Destroy buffer
14.Which molecule can hydrogen bond with water?
A. CH■
B. CO■
C. NH■
D. O■
15.Which statement about buffers is correct?
A. Prevent pH change completely
B. Only work at pH 7
C. Resist changes in pH
D. Neutralize acids fully
Gibbs Free Energy Questions
16.Which condition results in a spontaneous reaction?
A. G > 0
B. G = 0
C. G < 0
D. H > 0
