Question 1

"Proton hopping" essentially means that:

Accepted Answer

A)  an individual proton "jumps" from one electronegative group to the next. 
B)  a free proton moves from one hydroxyl group of ionized water to the next. 
C)  several protons move between hydrogen bonded water molecules causing the net movement of a photon over a long distance in a short time. 
D)  individual protons are freer to move among and between water molecules in solution. 
E)  hydronium ions are freer to move among and between water molecules in solution. 
A)  an individual proton "jumps" from one electronegative group to the next. 
B)  a free proton moves from one hydroxyl group of ionized water to the next. 
C)  several protons move between hydrogen bonded water molecules causing the net movement of a photon over a long distance in a short time. 
D)  individual protons are freer to move among and between water molecules in solution. 
E)  hydronium ions are freer to move among and between water molecules in solution.

Question 2

Phosphoric acid is tribasic, with pKa's of 2.14, 6.86, and 12.4. The ionic form that predominates at pH 3.2 is:

Accepted Answer

A)  H3PO4. 
B)  H2PO4-. 
C)  HPO42-. 
D)  PO43-. 
E)  None of the answers is correct. 
A)  H3PO4. 
B)  H2PO4-. 
C)  HPO42-. 
D)  PO43-. 
E)  None of the answers is correct.

Question 3

You have just made a solution by combining 50 mL of a 0.1 M sodium acetate solution with 150 mL of 1 M acetic acid (pKa = 4.7). What is the pH of the resulting solution?

Accepted Answer

To calculate the pH of the resulting sol

Question 4

Explain the fact that ethanol (CH3CH2OH) is more soluble in water than is ethane (CH3CH3).

Accepted Answer

Ethanol (C2H5OH) is more soluble in wate

Question 5

Give an example of a biological reaction in which water participates as a reactant and a reaction in which it participates as a product.

Accepted Answer

Certainly! Water can participate in biol

Question 6

H+ + HCO3- $\Delta$ H2CO3 $\Delta$ CO2 + H2O
Severe diarrhea is accompanied by a loss of HCO3-. If untreated, will the condition result in acidosis or alkalosis? Use the bicarbonate buffer system given in the scheme above and Le Chatelier's Principle to explain your answer.

Accepted Answer

The condition of severe diarrhea, which

Question 7

Which force plays the GREATEST role in stabilizing biological structures in membranes?

Accepted Answer

A)  hydrogen bonding, because it a strong non-covalent bond 
B)  hydrophobic interactions that increase solvent entropy 
C)  covalent interactions, because they are very stable interactions 
D)  electrostatic interactions between oppositely charged ions 
E)  van der Waals interactions, because of the attraction between transient dipoles 
A)  hydrogen bonding, because it a strong non-covalent bond 
B)  hydrophobic interactions that increase solvent entropy 
C)  covalent interactions, because they are very stable interactions 
D)  electrostatic interactions between oppositely charged ions 
E)  van der Waals interactions, because of the attraction between transient dipoles

Question 8

When water is found in a crystal structure of a biomolecule, which statement is NOT true?

Accepted Answer

A)  The properties of the bound water molecules are different from those of the "bulk" water of the solvent. 
B)  The bound water molecules may provide a path for "proton hopping." 
C)  The bound water molecules can form an essential part of the protein's ligand binding site. 
D)  The orientation of bound water molecules is precise. 
E)  All of the statements are true. 
A)  The properties of the bound water molecules are different from those of the "bulk" water of the solvent. 
B)  The bound water molecules may provide a path for "proton hopping." 
C)  The bound water molecules can form an essential part of the protein's ligand binding site. 
D)  The orientation of bound water molecules is precise. 
E)  All of the statements are true.

Question 9

Which statement about hydrogen bonds is NOT true?

Accepted Answer

A)  Hydrogen bonds are highly directional. 
B)  Hydrogen bonds are capable of holding molecules in a specific geometric arrangement. 
C)  Hydrogen bonds are strongest when the three atoms in the bond are in a straight line. 
D)  Hydrogen bonds are strongest when the oxygen atom is perpendicular to the hydrogen donor. 
E)  Hydrogen bonds place a hydrogen ion directly between two partial negative charges. 
A)  Hydrogen bonds are highly directional. 
B)  Hydrogen bonds are capable of holding molecules in a specific geometric arrangement. 
C)  Hydrogen bonds are strongest when the three atoms in the bond are in a straight line. 
D)  Hydrogen bonds are strongest when the oxygen atom is perpendicular to the hydrogen donor. 
E)  Hydrogen bonds place a hydrogen ion directly between two partial negative charges.

Question 10

The pH of a sample of blood is 7.4, while gastric juice is pH 1.4. The blood sample has:

Accepted Answer

A)  0.189 times the [H+] as the gastric juice. 
B)  5.29 times lower [H+] than the gastric juice. 
C)  6 times lower [H+] than the gastric juice. 
D)  6000 times lower [H+] than the gastric juice. 
E)  one million times lower [H+] than the gastric juice. 
A)  0.189 times the [H+] as the gastric juice. 
B)  5.29 times lower [H+] than the gastric juice. 
C)  6 times lower [H+] than the gastric juice. 
D)  6000 times lower [H+] than the gastric juice. 
E)  one million times lower [H+] than the gastric juice.

Question 11

A weak acid HA, has a pKa of 5.0. If 1.0 mol of this acid and 0.1 mol of NaOH were dissolved in one liter of water, what would the final pH be?

Accepted Answer

To solve this problem, we need to unders

Question 12

Give the general Henderson-Hasselbalch equation and indicate the region in which the buffering capacity of the system is greatest.

Accepted Answer

The Henderson-Hasselbalch equation is a

Question 13

Dissolving a nonpolar solute in water _____ the order of the solvent and _____ the dynamic interplay among water molecules that occurs in pure water.

Accepted Answer

A)  increases; decreases 
B)  increases; increases 
C)  decreases; decreases 
D)  decreases; increases 
E)  decreases; stabilizes 
A)  increases; decreases 
B)  increases; increases 
C)  decreases; decreases 
D)  decreases; increases 
E)  decreases; stabilizes

Question 14

Distilled white vinegar has a pH of 2.4 Water as a Reactant. What is the [H+] of distilled white vinegar?

Accepted Answer

A)  2.4 Water as a Reactant0 × 100 M 
B)  2.5 The Fitness of the Aqueous Environment1 × 10-12 M 
C)  2.5 The Fitness of the Aqueous Environment1 × 10-3M 
D)  3.98 × 10-3 M 
E)  3.98 × 10-6 M 
A)  2.4 Water as a Reactant0 × 100 M 
B)  2.5 The Fitness of the Aqueous Environment1 × 10-12 M 
C)  2.5 The Fitness of the Aqueous Environment1 × 10-3M 
D)  3.98 × 10-3 M 
E)  3.98 × 10-6 M

Question 15

The ionization of water is due to the strongly electronegative element:

Accepted Answer

A)  hydrogen donating an electron to oxygen. 
B)  oxygen donating an electron to hydrogen. 
C)  hydrogen receiving an electron from oxygen. 
D)  oxygen receiving an electron from hydrogen. 
E)  None of the answers is correct. 
A)  hydrogen donating an electron to oxygen. 
B)  oxygen donating an electron to hydrogen. 
C)  hydrogen receiving an electron from oxygen. 
D)  oxygen receiving an electron from hydrogen. 
E)  None of the answers is correct.

Question 16

Milk of magnesia has a pH of 10.2. What is the [OH-] of milk of magnesia?

Accepted Answer

A)  6.31 × 10-11 M 
B)  1.58 × 10-4 M 
C)  1.58 × 10-5 M 
D)  1.02 × 10-3 M 
E)  6.31 × 10-4 M 
A)  6.31 × 10-11 M 
B)  1.58 × 10-4 M 
C)  1.58 × 10-5 M 
D)  1.02 × 10-3 M 
E)  6.31 × 10-4 M

Question 17

Speculate why weak forces, not strong forces, are the basis for molecular recognition among biomolecules.

Accepted Answer

Weak forces, such as hydrogen bonding, v

Question 18

Camels live in very dry habitats and do not need to consume water as frequently as animals in wetter habitats. What is a partial reason for this?

Accepted Answer

A)  Metabolic water is produced by oxidation of fuels such as glucose. 
B)  Metabolic water is produced by acid/base dehydration reactions. 
C)  Metabolic water is produced by symbiotic bacteria in the camel's gut. 
D)  Metabolic water is produced by splitting carbon dioxide. 
E)  None of the answers is correct. 
A)  Metabolic water is produced by oxidation of fuels such as glucose. 
B)  Metabolic water is produced by acid/base dehydration reactions. 
C)  Metabolic water is produced by symbiotic bacteria in the camel's gut. 
D)  Metabolic water is produced by splitting carbon dioxide. 
E)  None of the answers is correct.

Question 19

A compound is known to have a free amino group with a pKa of 8.8, and one other ionizable group with a pKa between 5 and 7. To 100 mL of a 0.2 M solution of this compound at pH 8.2 was added 40 mL of a solution of 0.2 M hydrochloric acid. The pH changed to 6.2. The pKa of the second ionizable group is:

Accepted Answer

A)  The pH cannot be determined from this information. 
B)  5.4. 
C)  5.6. 
D)  6.0. 
E)  6.2. 
A)  The pH cannot be determined from this information. 
B)  5.4. 
C)  5.6. 
D)  6.0. 
E)  6.2.

Question 20

Dissolved solutes alter some physical (colligative) properties of the solvent water because they change the:

Accepted Answer

A)  concentration of the water. 
B)  hydrogen bonding of the water. 
C)  ionic bonding of the water. 
D)  pH of the water. 
E)  temperature of the water. 
A)  concentration of the water. 
B)  hydrogen bonding of the water. 
C)  ionic bonding of the water. 
D)  pH of the water. 
E)  temperature of the water.

Exam 2: Water

"Proton hopping" essentially means that:

Phosphoric acid is tribasic, with pKa's of 2.14, 6.86, and 12.4. The ionic form that predominates at pH 3.2 is:

You have just made a solution by combining 50 mL of a 0.1 M sodium acetate solution with 150 mL of 1 M acetic acid (pKa = 4.7). What is the pH of the resulting solution?

Explain the fact that ethanol (CH3CH2OH) is more soluble in water than is ethane (CH3CH3).

Give an example of a biological reaction in which water participates as a reactant and a reaction in which it participates as a product.

H+ + HCO3- Δ\DeltaΔ H2CO3 Δ\DeltaΔ CO2 + H2O Severe diarrhea is accompanied by a loss of HCO3-. If untreated, will the condition result in acidosis or alkalosis? Use the bicarbonate buffer system given in the scheme above and Le Chatelier's Principle to explain your answer.

Which force plays the GREATEST role in stabilizing biological structures in membranes?

When water is found in a crystal structure of a biomolecule, which statement is NOT true?

Which statement about hydrogen bonds is NOT true?

The pH of a sample of blood is 7.4, while gastric juice is pH 1.4. The blood sample has:

A weak acid HA, has a pKa of 5.0. If 1.0 mol of this acid and 0.1 mol of NaOH were dissolved in one liter of water, what would the final pH be?

Give the general Henderson-Hasselbalch equation and indicate the region in which the buffering capacity of the system is greatest.

Dissolving a nonpolar solute in water _____ the order of the solvent and _____ the dynamic interplay among water molecules that occurs in pure water.

Distilled white vinegar has a pH of 2.4 Water as a Reactant. What is the [H+] of distilled white vinegar?

The ionization of water is due to the strongly electronegative element:

Milk of magnesia has a pH of 10.2. What is the [OH-] of milk of magnesia?

Speculate why weak forces, not strong forces, are the basis for molecular recognition among biomolecules.

Camels live in very dry habitats and do not need to consume water as frequently as animals in wetter habitats. What is a partial reason for this?

Dissolved solutes alter some physical (colligative) properties of the solvent water because they change the:

The Foundations of Biochemistry

Amino Acids, Peptides, and Proteins

The Three-Dimensional Structure of Proteins

Protein Function

Enzymes

Carbohydrates and Glycobiology

Nucleotides and Nucleic Acids

DNA-Based Information Technologies

Lipids

Biological Membranes and Transport

Biosignaling

Bioenergetics and Biochemical Reaction Types

Glycolysis, Gluconeogenesis, and the Pentose Phosphate Pathway

Principles of Metabolic Regulation

The Citric Acid Cycle

Fatty Acid Catabolism

Amino Acid Oxidation and the Production of Urea

Oxidative Phosphorylation and Photophosphorylation

Carbohydrate Biosynthesis in Plants and Bacteria

Lipid Biosynthesis

Biosynthesis of Amino Acids, Nucleotides, and Related Molecules

Hormonal Regulation and Integration of Mammalian Metabolism

Genes and Chromosomes

DNA Metabolism

RNA Metabolism

Protein Metabolism

Regulation of Gene Expression

Filters

Phosphoric acid is tribasic, with pK_a's of 2.14, 6.86, and 12.4. The ionic form that predominates at pH 3.2 is:

You have just made a solution by combining 50 mL of a 0.1 M sodium acetate solution with 150 mL of 1 M acetic acid (pK_a = 4.7). What is the pH of the resulting solution?

Explain the fact that ethanol (CH₃CH₂OH) is more soluble in water than is ethane (CH₃CH₃).

H⁺ + HCO₃^- $\Delta$ H₂CO₃ $\Delta$ CO₂ + H₂O Severe diarrhea is accompanied by a loss of HCO₃^-. If untreated, will the condition result in acidosis or alkalosis? Use the bicarbonate buffer system given in the scheme above and Le Chatelier's Principle to explain your answer.

A weak acid HA, has a pK_a of 5.0. If 1.0 mol of this acid and 0.1 mol of NaOH were dissolved in one liter of water, what would the final pH be?

Dissolving a nonpolar solute in water _ the order of the solvent and _ the dynamic interplay among water molecules that occurs in pure water.

Distilled white vinegar has a pH of 2.4 Water as a Reactant. What is the [H⁺] of distilled white vinegar?

Milk of magnesia has a pH of 10.2. What is the [OH^-] of milk of magnesia?