Electrochemistry

Galvanic Cell

use redox rxns to create electrical E

Galvanic cells are also known as

voltaic cells

what direction is e- flow in?

anode to cathode

Electrode

metal surfaces where oxidation + reduction occur

Anode vs Cathode Charge

anode: -ve

cathode: +ve

Anode vs Cathode Redox rxn

anode: oxidation

cathode: reduction

Anode vs Cathode losing/gaining e-

anode: losing

cathode: gaining

Anode vs Cathode charge increases/decreases as rxn continues

anode: increasing

cathode: decreasing

Electrolyte Solution

solution in each half cell that contains a dissolved ionic cpd

its -ve ions balance the increasingly +ve charge of the anode

its +ve ions balance the increasingly -ve charge of the cathode

Salt Bridge

• completes the electric circuit

• keeps the cell neutral by giving its +ve and -ve ions to the cathode and anode respectively

Potential Difference

difference in potential Es between the anode and cathode

measured in volts

Electromotive Force (emf)

the force causing the movement of e-

2 Common Types of Voltaic Cells

1. Dry cell

2. Lead cell

Dry Cell vs Lead Cell

dry cell: electrolyte in the form of a paste; uses: flashlights, calculators, watches, PEDs, etc.

lead cell: uses lead as one of the electrodes; uses: car batteries

Standard Cell Potential/Standard emf

E˚_cell

Standard Cell Potential/Standard emf formula

E˚_cell = E_{r cathode} - E_{r anode}

The more +ve the reduction potential is, the more likely the metal will be ________ (be the ______)

reduced, cathode

If the cell potential (E˚_cell) is +ve, the net rxn will be __________.

spontaneous