CHEM 212 exam 2 Portage learning FALL2025

biochem exam 2

1. Calculate pH with this equation: pH = - log [H+]

2. Calculate Gibbs free energy change with this equation: ΔG = ΔH -
TΔS

(T must be in Kelvin)

3. The pH of a solution of 0.0010 M NaOH is: hydrogen
and oxygen
A. 1 C. The
B. 11 unequal
C. 8 electron
D. 0 sharing
between
hydrogen



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
E. All of the answers are correct

5. The bent shape (104.5 degrees) of water is due
to
.

A. The dipole arrows in a water molecule
B. The electronegativity difference between
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B. 11

Kw=[H+ ][OH- ] = 1.0 x
10⁻¹⁴
Kw=[H+ ][0.0010] = 1.0 x
10⁻¹⁴
= [H+ ]=1.0 x 10⁻¹¹
pH=-log[1.0 x 10⁻¹¹]
=11

E. All of the answers are correct




D. The unshared electron pairs on the oxygen atom




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and oxygen
D. The unshared electron pairs on the oxygen atom

6. The H+ concentration of a solution is 1.2 x 10⁻³ M. What 2.92
is the pH?

7. If the Ka of an acid is 5.63 x 10⁻³, what is B. 2.25
the pKa?
[pKa = -log(5.63 x 10⁻³)
A. 6.86 = 2.25]
B. 2.25
C. 5.63
D. 10.12
E. 1.38
C. Phosphoric acid,
8. List the acids in DECREASING order of nitrous acid, acetic
strength (strongest to weakest): acid
Nitrous acid, acetic acid, phosphoric acid

A. Nitrous acid, acetic acid, phosphoric acid
B. Acetic acid, nitrous acid, phosphoric acid
C. Phosphoric acid, nitrous acid, acetic acid
D. Acetic acid, phosphoric acid, nitrous acid
D. 2.9
9. The pH of a solution of 8.9 x 10⁻¹²M NaOH
is:
[Kw=[H+][OH-] = 1.0
x 10-14;
A. 8.9
[H+][8.9 x 10-12] = 1.0
B. 8.9 x 10⁻¹²
x
C. 4.8 10-14;
D. 2.9 [H+]=890
pH=-log[890]=2.9]

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