Question 1

In a titration of a weak acid by a strong base

Accepted Answer

A)  two equivalents of base are always needed to neutralize all the acid present 
B)  the equivalence point cannot be defined exactly 
C)  there is a region in which the pH changes slowly 
D)  the equivalence point depends on the nature of the added base 
A)  two equivalents of base are always needed to neutralize all the acid present 
B)  the equivalence point cannot be defined exactly 
C)  there is a region in which the pH changes slowly 
D)  the equivalence point depends on the nature of the added base

Question 2

Using the Henderson-Hasselbalch equation,calculate the pH of an ammonia buffer when the NH3:NH4+ ratio is 0.4 moles:0.6 moles.(pK = 9.75)

Accepted Answer

A)  7.40 
B)  9.07 
C)  9.25 
D)  9.43 
E)  11.05 
A)  7.40 
B)  9.07 
C)  9.25 
D)  9.43 
E)  11.05

Question 3

Which of the following molecules will not form hydrogen bonds?

Accepted Answer

A)  CH4 
B)  NH3 
C)  H2O 
D)  HF 
A)  CH4 
B)  NH3 
C)  H2O 
D)  HF

Question 4

Which of the following compounds is most likely to form a micelle?

Accepted Answer

A)  Acetic acid. 
B)  Glucose. 
C)  Glycerol. 
D)  Sodium palmitate. 
E)  Sodium phosphate. 
A)  Acetic acid. 
B)  Glucose. 
C)  Glycerol. 
D)  Sodium palmitate. 
E)  Sodium phosphate.

Question 5

The pOH a solution of 0.04 M HCl is:

Accepted Answer

A)  1.4 
B)  10 
C)  12.6 
D)  13.6 
E)  The pOH cannot be determined 
A)  1.4 
B)  10 
C)  12.6 
D)  13.6 
E)  The pOH cannot be determined

Question 6

Which of the following is a correct listing of electronegativity values,from low to high?

Accepted Answer

A)  C, H, O, N 
B)  N, H, O, C 
C)  H, C, N, O 
D)  H, C, O, N 
A)  C, H, O, N 
B)  N, H, O, C 
C)  H, C, N, O 
D)  H, C, O, N

Question 7

The main blood buffer system is

Accepted Answer

A)  H2CO3/HCO3- 
B)  HCO3-/CO32- 
C)  H2CO3/CO32- 
D)  none of the above 
A)  H2CO3/HCO3- 
B)  HCO3-/CO32- 
C)  H2CO3/CO32- 
D)  none of the above

Question 8

Which of the following characteristics makes for a good hydrogen bond acceptor?

Accepted Answer

A)  a high electronegativity 
B)  a nonbonding pair of electrons 
C)  both of these 
D)  neither of these 
A)  a high electronegativity 
B)  a nonbonding pair of electrons 
C)  both of these 
D)  neither of these

Question 9

Which of the following is not true?

Accepted Answer

A)  A buffer is a solution which maintains a solution at a neutral pH 
B)  Buffer solutions are made to resist change in pH 
C)  Zwitterion buffers are less likely to interfere with biological reactions than non-zwitterions 
D)  HEPES is a zwitterion buffer 
A)  A buffer is a solution which maintains a solution at a neutral pH 
B)  Buffer solutions are made to resist change in pH 
C)  Zwitterion buffers are less likely to interfere with biological reactions than non-zwitterions 
D)  HEPES is a zwitterion buffer

Question 10

If the pH of 1 liter of a 1.0 M carbonate buffer is 7.0,what is the molar ratio of H2CO3 to HCO3-? (pK = 6.37)

Accepted Answer

A)  0.234 
B)  4.27 
C)  6.37 
D)  7.00 
E)  10.20 
A)  0.234 
B)  4.27 
C)  6.37 
D)  7.00 
E)  10.20

Question 11

Which has the greater Ka,a weak acid or a strong acid?

Accepted Answer

A)  A weak acid. 
B)  A strong acid 
C)  They should dissociate about the same. 
D)  It's impossible to predict. 
A)  A weak acid. 
B)  A strong acid 
C)  They should dissociate about the same. 
D)  It's impossible to predict.

Question 12

Ionic compounds and polar covalent compounds tend to dissolve in water because of

Accepted Answer

A)  ion-dipole and dipole-dipole interactions 
B)  dipole-induced dipole interactions 
C)  van der Waals bonds 
D)  hydrophobic interactions 
A)  ion-dipole and dipole-dipole interactions 
B)  dipole-induced dipole interactions 
C)  van der Waals bonds 
D)  hydrophobic interactions

Question 13

Which of the following characteristics makes for a good hydrogen bond donor?

Accepted Answer

A)  a high electronegativity 
B)  a nonbonding pair of electrons 
C)  both of the above 
D)  neither of the above 
A)  a high electronegativity 
B)  a nonbonding pair of electrons 
C)  both of the above 
D)  neither of the above

Question 14

Bases are

Accepted Answer

A)  proton donors. 
B)  proton acceptors. 
C)  hydrogen bond donors. 
D)  hydrogen bond acceptors. 
A)  proton donors. 
B)  proton acceptors. 
C)  hydrogen bond donors. 
D)  hydrogen bond acceptors.

Question 15

Many of the properties of water can be accounted for by the fact that

Accepted Answer

A)  it is polar 
B)  it forms hydrogen bonds 
C)  it is a bent molecule 
D)  all of these are true 
A)  it is polar 
B)  it forms hydrogen bonds 
C)  it is a bent molecule 
D)  all of these are true

Question 16

A solution at pH 7 contains a weak acid,HA.The pKa of the acid is 6.5.What is the ratio of [A-]:[HA]?

Accepted Answer

A)  1:3 
B)  1:1 
C)  3:1 
D)  10:1 
A)  1:3 
B)  1:1 
C)  3:1 
D)  10:1

Question 17

Exhibit 2A   The structure of ATP with various groups labeled.
Group III is the entire phosphate group.
Refer to Exhibit 2A.Which of the functional groups is the most electrophilic?

Accepted Answer

A)  I 
B)  II 
C)  III 
D)  IV 
E)  The answer cannot be determined without further information. 
A)  I 
B)  II 
C)  III 
D)  IV 
E)  The answer cannot be determined without further information.

Question 18

Which of the following acids would serve as a good buffer for a reaction at pH = 8.0?

Accepted Answer

A)  I 
B)  II 
C)  III 
D)  IV 
A)  I 
B)  II 
C)  III 
D)  IV

Question 19

Which of the following elements has the highest electronegativity?

Accepted Answer

A)  C 
B)  H 
C)  N 
D)  O 
E)  P 
A)  C 
B)  H 
C)  N 
D)  O 
E)  P

Exam 2: Water: The Solvent for Biochemical Reactions

In a titration of a weak acid by a strong base

Using the Henderson-Hasselbalch equation,calculate the pH of an ammonia buffer when the NH3:NH4+ ratio is 0.4 moles:0.6 moles.(pK = 9.75)

Which of the following molecules will not form hydrogen bonds?

Which of the following compounds is most likely to form a micelle?

The pOH a solution of 0.04 M HCl is:

Which of the following is a correct listing of electronegativity values,from low to high?

The main blood buffer system is

Which of the following characteristics makes for a good hydrogen bond acceptor?

Which of the following is not true?

If the pH of 1 liter of a 1.0 M carbonate buffer is 7.0,what is the molar ratio of H2CO3 to HCO3-? (pK = 6.37)

Which has the greater Ka,a weak acid or a strong acid?

Ionic compounds and polar covalent compounds tend to dissolve in water because of

Which of the following characteristics makes for a good hydrogen bond donor?

Bases are

Many of the properties of water can be accounted for by the fact that

A solution at pH 7 contains a weak acid,HA.The pKa of the acid is 6.5.What is the ratio of [A-]:[HA]?

Exhibit 2A The structure of ATP with various groups labeled. Group III is the entire phosphate group. Refer to Exhibit 2A.Which of the functional groups is the most electrophilic?

Which of the following acids would serve as a good buffer for a reaction at pH = 8.0?

Which of the following elements has the highest electronegativity?

Biochemistry and the Organization of Cells

Amino Acids and Peptides

The Three-Dimensional Structure of Proteins

Protein Purification and Characterization Techniques

The Behavior of Proteins: Enzymes

The Behavior of Proteins: Enzymes, Mechanisms, and Control

Lipids and Proteins Are Associated in Biological Membranes

Nucleic Acids: How Structure Conveys Information

Biosynthesis of Nucleic Acids: Replication

Transcription of the Genetic Code: Biosynthesis of Rna

Protein Synthesis: Translation of the Genetic Message

Nucleic Acid Biotechnology Techniques

Viruses, Cancer, and Immunology

The Importance of Energy Changes and Electron Transfer in Metabolism

Carbohydrates

Glycolysis

Storage Mechanisms and Control in Carbohydrate Metabolism

The Citric Acid Cycle

Electron Transport and Oxidative Phosphorylation

Lipid Metabolism

Photosynthesis

The Metabolism of Nitrogen

Integration of Metabolism: Cellular Signaling

Filters

Using the Henderson-Hasselbalch equation,calculate the pH of an ammonia buffer when the NH₃:NH₄⁺ ratio is 0.4 moles:0.6 moles.(pK = 9.75)

If the pH of 1 liter of a 1.0 M carbonate buffer is 7.0,what is the molar ratio of H₂CO₃ to HCO₃^-? (pK = 6.37)

Which has the greater K_a,a weak acid or a strong acid?

A solution at pH 7 contains a weak acid,HA.The pK_a of the acid is 6.5.What is the ratio of [A^-]:[HA]?