Biochemistry Module 2 Exam Challenge
with Solutions 2023-2024.
The pH of a solution of 0.0010 M NaOH is: - Answer: 11 (Kw=[H+][OH-] = 1.0 x 10-
14; [H+][0.0010] = 1.0 x 10-14 [H+]=1.0 x 10-11; pH=-log[1.0 x 10-11]=11)
The bent shape of water is due to ______________. - Answer: The unshared
electron pairs on the oxygen atom
The H+ concentration of a solution is 1.2 x 10-3 M. What is the pH? - Answer: 2.92
If the Ka of an acid is 5.63 x 10-3, what is the pKa? - Answer: 2.25 ([pKa = -log(5.63
x 10-3) = 2.25])
List the acids in DECREASING order of strength (strongest to weakest): Nitrous acid
(Ka = 4.0 x 10-4); acetic acid (Ka = 1.7 x 10-5); phosphoric acid (Ka = 7.3 x 10-3) -
Answer: Phosphoric acid, nitrous acid, acetic acid
Elemental iodine (I2) is a solid at room temperature. What is the dominant
attractive force that exists between I2 molecules in the solid? - Answer: London
forces
Which one of the following molecules can form a hydrogen bond? (A.) HBr (B.) HCl
(C.) NH3 (D.) CH4 (E.) H2 - Answer: C. NH3
, A hydrogen bond can form between a hydrogen atom bonded to oxygen, O-H, and
________. - Answer: N
In a bond between P and Cl, there exists a difference in electronegativity resulting
in partial positive and partial negative charges. If a dipole arrow were added to
this structure, which way would the arrow point? - Answer: The arrow points from
N toward Br
The following reaction occurs in glues purchased from hardware stores.
Customers use this product to glue plastic together. Epoxy (l) + hardener (l) ⟶
Glue (s) + heat given off What is the sign (+ or -) of the change in Δ G and Δ H? -
Answer: Δ G is (-) and Δ H is (-)
Which of the following is the free-energy change of a reaction? - Answer: Δ G
Which buffer system is used by the renal system to maintain pH balance? -
Answer: Bicarbonate buffer system
A buffer can neutralize acid and base within a certain limit. We say that this is its: -
Answer: Buffer capacity
Is a pH of 8.36 acidic, neutral, or basic? - Answer: Basic
with Solutions 2023-2024.
The pH of a solution of 0.0010 M NaOH is: - Answer: 11 (Kw=[H+][OH-] = 1.0 x 10-
14; [H+][0.0010] = 1.0 x 10-14 [H+]=1.0 x 10-11; pH=-log[1.0 x 10-11]=11)
The bent shape of water is due to ______________. - Answer: The unshared
electron pairs on the oxygen atom
The H+ concentration of a solution is 1.2 x 10-3 M. What is the pH? - Answer: 2.92
If the Ka of an acid is 5.63 x 10-3, what is the pKa? - Answer: 2.25 ([pKa = -log(5.63
x 10-3) = 2.25])
List the acids in DECREASING order of strength (strongest to weakest): Nitrous acid
(Ka = 4.0 x 10-4); acetic acid (Ka = 1.7 x 10-5); phosphoric acid (Ka = 7.3 x 10-3) -
Answer: Phosphoric acid, nitrous acid, acetic acid
Elemental iodine (I2) is a solid at room temperature. What is the dominant
attractive force that exists between I2 molecules in the solid? - Answer: London
forces
Which one of the following molecules can form a hydrogen bond? (A.) HBr (B.) HCl
(C.) NH3 (D.) CH4 (E.) H2 - Answer: C. NH3
, A hydrogen bond can form between a hydrogen atom bonded to oxygen, O-H, and
________. - Answer: N
In a bond between P and Cl, there exists a difference in electronegativity resulting
in partial positive and partial negative charges. If a dipole arrow were added to
this structure, which way would the arrow point? - Answer: The arrow points from
N toward Br
The following reaction occurs in glues purchased from hardware stores.
Customers use this product to glue plastic together. Epoxy (l) + hardener (l) ⟶
Glue (s) + heat given off What is the sign (+ or -) of the change in Δ G and Δ H? -
Answer: Δ G is (-) and Δ H is (-)
Which of the following is the free-energy change of a reaction? - Answer: Δ G
Which buffer system is used by the renal system to maintain pH balance? -
Answer: Bicarbonate buffer system
A buffer can neutralize acid and base within a certain limit. We say that this is its: -
Answer: Buffer capacity
Is a pH of 8.36 acidic, neutral, or basic? - Answer: Basic
