Galvanic Cells Flashcards
What is a galvanic or voltaic cell?
An electrochemical cell that uses a spontaneous redox reaction to create a flow of electrons
How are the oxidation and reduction reactions placed in the cell?
They are physically separated but connected by a wire and an electrolyte
If a half reaction involves a metal, what does the metal function as?
- The electrode
- The conductor that carries the charge into an out of an electrolyte
If a half reaction does not involve a metal, what acts as the electrode?
- An inert electrode made out of platinum, silver or gold is used
- Electrodes are connected with a metal wire
Where does the reaction take place?
At the surface of the electrodes
Anode
The electrode where oxidation takes place
Cathode
The electrode where reduction takes place
What is the purpose of a salt bridge?
- Allows negative and positive ions to move to the other contained
- Maintains the electrical neutrality of the two solutions
What does a salt bridge contain?
- A neutral salt
- Solution that is inert (not involved in the redox reaction itself)
Examples of neutral salts
- NaCl
- KCl
- KNO3
Notation for an electrochemical cell
The anode appears on the left, cathode on the right
What do single vertical lines indicate?
The contact boundaries between phases in each half cell
What do double vertical lines indicate?
The salt bridge, porous cup or separator
Flow of electrons
From the anode to the cathode
Does the cation in the salt bridge travel to the anode or cathode?
Cathode
