Question 1
3 / 3 pts
Scientific Calculator
The pH of a solution of 8.9 x 10-12 M NaOH is:
A. 8.9
B. 8.9 x 10-12
C. 4.8
D. 11
E. 2.9
A
B
C
D
Correct!
E
[Kw=[H+][OH-] = 1.0 x 10-14; [H+][8.9 x 10-12] =
...
Question 1
3 / 3 pts
Scientific Calculator
The pH of a solution of 8.9 x 10-12 M NaOH is:
A. 8.9
B. 8.9 x 10-12
C. 4.8
D. 11
E. 2.9
A
B
C
D
Correct!
E
[Kw=[H+][OH-] = 1.0 x 10-14; [H+][8.9 x 10-12] = 1.0 x 10-14 ;[H+]=890;
pH=-log[890]=2.9]
Question 2
3 / 3 pts
Water is a unique molecule. Which of the following contributes to water’s unique place
Portage Learning Chem 210 Module 2 Exam
in the chemical world?
The geometry of the molecule
The polarity of the O-H bonds
The ability of water molecules to hydrogen bond
The bond angle of water
All of the answers are correct
ALL OF THE ANSWERS ARE CORRECT
What factor contributes to the bent shape of a water molecule?
The dipole arrows in a water molecule
The unshared electron pairs on the oxygen atom
The electronegativity difference between hydrogen and oxygen
The unequal electron sharing between hydrogen and oxygen
None of the answers are correct
THE UNSHARED ELECTRON PAIRS ON THE OXYGEN ATOM
Question 4
3 / 3 pts
Which diagrams correctly represent a hydrogen bond?
A and B
A and D
B and C
C and D
A and C
A AND C
BOTH SHOW A PROTON DONOR AND ACCEPTOR
Question 5
3 / 3 pts
Scientific Calculator
The H+ concentration of a solution is 5.6 x 10-5 What is the pH?
-4.25
Correct!
4.25
[ [H+]=5.6 x 10-5; pH=-log[5.6 x 10-5]=4.25]
5.65
-9.75
9.75
4.25
[ [H+]=5.6 x 10-5; pH=-log[5.6 x 10-5]=4.25]
If the Ka of an acid is 2.67 x 10-5, what is the pKa?
7.45
12.25
5.26
2.67
4.57
4.57
[pKa = -log(2.67 x 10-5) = 4.57]
Question 7
3 / 3 pts
List the acids in INCREASING order of strength (weakest to strongest):
Nitrous acid (Ka = 4.0 x 10-4); acetic acid (Ka = 1.7 x 10-5); phosphoric acid (Ka = 7.3 x
10-3)
Nitrous acid, acetic acid, phosphoric acid
Acetic acid, nitrous acid, phosphoric acid
Phosphoric acid, nitrous acid, acetic acid
Acetic acid, phosphoric acid, nitrous acid
None of the above
ACETIC ACID, NITROUS ACID, PHOSPHORIC ACID
Question 8
3 / 3 pts
Elemental bromine (Br2) is a liquid at room temperature. What is the dominant
attractive force that exists between Br2 molecules in the liquid?
Halogen forces
Dipole-dipole forces
Hydrogen bonds
Covalent bonds
London forces
LONDON FORCES
Which one of the following molecules can form a hydrogen bond?
A. HBr
B. HCl
C. NH3
D. CH4
E. H2
C. NH3
Question 10
3 / 3 pts
A hydrogen bond can form between a hydrogen atom bonded to nitrogen, N–H, and
________.
C
O
Cl
P
Br
O
Question 11
3 / 3 pts
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?
The arrow points from Br toward N
The arrow points from N toward Br
Two arrows; one pointed in each direction
There would not be a dipole arrow in this case.
None of the above
THE ARROW POINTS FROM N TOWARD BR
Question 12
3 / 3 pts
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 of
What is the sign (+ or -) of the change in
Δ
ΔG and
Δ
ΔH?
A)
ΔG is (+) and ΔH is (-)
B) ΔG is (-) and ΔH is (-)
C) ΔG is (-) and ΔH is (+)
D) ΔG is (+) and ΔH is (+)
E) None of the above
B) ΔG is (-) and ΔH is (-)
Question 13
3 / 3 pts
Which of the following is the free-energy change of a reaction?
A) G
B) ΔS
C) ΔH
D) ΔG
E) All of the above
D) ΔG
Question 14
3 / 3 pts
Which of the following is the change in entropy of a reaction?
A) ΔG
B) ΔE
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