Fundamentals of
Electrochemistry
Lecture 2 of x, Chapter 13
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Activity 1
Understanding Galvanic Cells
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Galvanic Cells
A galvanic cell uses a spontaneous chemical reaction
to generate electricity.
What are the key components?
Anode?
Cathode?
Salt bridge?
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Drawing a Galvanic Cell
Can you sketch out the Danielle Cell in its entirety?
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Analyze This Cell
Anode?
Cathode?
To force electrons to go
through potentiometer, the two
electrodes must not be contact.
Look in the diagram. How are
the electrodes separated?
Half-reactions at each
electrode?
How is this cell different from
Danielle cell?
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Analyze This Cell
Does this galvanic cell
work?
Meaning do electrons
flow from anode,
potentiometer, and
cathode?
Why or why not?
What happens at the
surface of Cd electrode
when Cd oxidizes?
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Line Diagram
A line diagram is a notation for describing a galvanic
cell.
| phase boundary (e.g., solid to liquid)
|| salt bridge (e.g., two different liquids)
What is a line diagram for the Danielle cell?
Note anode is written at extreme left-side of line and
cathode at extreme right-side.
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Problem 13-8
Write a line notation and two reduction half-reactions
for each cell pictured above.
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Problem 13-9
Draw a picture of the following cell and write
reduction half-reactions for each electrode:
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Activity 2
The Human Salt Bridge
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Human Salt Bridge
A salt bridge is an ionic medium with a semipermeable
barrier on each end.
Example: U-tube filled with agar and KCl, filter paper
soaked in saltwater, and you!
Human body is just a bag of salt housed in a
semipermeable membrane (i.e., skin)
Question: Can we measure a voltage from a Danielle
cell using filter paper, two fingers, and students
holding hands.
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Activity 3
How Do You Make a Battery?
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Making a Battery
Anode?
Cathode?
Salt bridge?
Half-reactions?
Materials: Pennies, nickels, paper, salt water, voltmeter
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