Modified True/False
Indicate
whether the sentence or statement is true or false. If false,
change the identified word or phrase to make the sentence or statement
true.
|
| |
1. |
Every
galvanic cell has two electrodes and at least one electrolyte.
____________________
|
| |
2. |
In
a galvanic cell, oxidation occurs at the cathode. ____________________
|
| |
3. |
In
a galvanic cell that involves two metal electrodes, the metal that is
higher on the activity series accepts electrons. ____________________
|
| |
4. |
Anions always move to the anode. ____________________
|
| |
5. |
Electrons always flow from the cathode to the anode. ____________________
|
| |
6. |
The
salt bridge in a galvanic cell must contain ions that do not react
with the other chemicals in the cell. ____________________
|
| |
7. |
The
size of the cell potential depends only on the electrodes that
are used to construct the galvanic cell. ____________________
|
| |
8. |
Given
two alkaline dry cells from the same manufacturer, the larger cell will
produce more electrical energy. ____________________
|
| |
9. |
The
electrolyte in an alkaline dry cell is acidic. ____________________
|
| |
10. |
Primary cells can be recharged. ____________________
|
| |
11. |
The
contents of nickel–cadmium batteries are bad for the environment.
____________________
|
Short Answer
|
| |
12. |
a.
Sketch a diagram of a galvanic cell that involves the following two
half-cells connected
by a salt bridge.
• half-cell 1: iron
nail in a solution of iron(II) sulfate, FeSO4(aq)
•
half-cell 2: copper strip in a solution of copper(II) sulfate, CuSO4(aq)
b.
What would be a suitable electrolyte for the salt bridge in this cell?
Why?
c.
Iron is oxidized because it is higher on the activity series than copper.
d.
Identify the anode. ____________________
e. Identify the cathode. ______________________
f. Write the anode half-reaction. _________________________________
g. Write the cathode
half-reaction. _________________________________
h. Write the overall
cell reaction. __________________________________
|
| |
13. |
In
any galvanic cell, the anode and cathode chemicals must remain separate.
Explain how they are separated in
a. a laboratory galvanic cell
b.
an alkaline dry cell
|
| |
14. |
The
following galvanic cells were constructed using nitrate solutions of
the same molar concentration: Mg/Ag, Zn/Ag, Fe/Ag, Cu/Ag. For
example, the Mg/Ag galvanic cell consists of
• an anode half-cell: a strip of magnesium in a solution of
magnesium nitrate
• a cathode half-cell: a strip of silver in
a solution of silver nitrate
a. Use the activity series to predict which cell
has the largest cell potential.
b. Which cell has the smallest cell potential?
|
| |
15. |
Figure 1 shows a simple galvanic cell, made by inserting
an inert graphite electrode into an aluminum pop can.
Figure 1
A
pop can cell
a. Before the connector is attached to the pop can, the point of
contact must be cleaned with sandpaper. Why?
b. What will happen to
the cell potential if the graphite electrode is allowed to touch the
bottom of the can? Why?
c.
How does the thickness of the aluminum change over time?
|
| |
16. |
Describe how fuel cells differ from primary cells.
|