1. Cells and Voltage

2. Explain the operation of a voltaic (galvanic) cell at the visual, particulate and symbolic level
Include: writing half-cell reactions and overall reaction
Additional KEY Terms
line notation anode cathode
salt bridge

3. Electrical current made with spontaneous redox
Volta ( )
Electrical current made with spontaneous redox
Half-cells are separated from each other
Transfer of electrons forced through wire
Load can be run with high enough voltage
Voltaic cells (also called Galvanic cells) use a spontaneous redox reaction to convert chemical energy into electrical energy

4. Electric current (I) – a flow of electrons.
e- move through conductors
redox e- transferred between metal electrodes
Voltage (V) – measure of e- ability to do work
also called electrical potential (E°)

5. The following applies to ALL electrochemical cells
node – electrode where xidation occurs o
e- produced at anode
negative electrode
athode – where eduction occurs C r
e- consumed at cathode
positive electrode

6. 2 Ag+(aq) + Cu(s) → 2 Ag(s) + Cu2+(aq)
Electrons will be transferred from copper to silver

7. electrons move from anode to cathode ("A to C")
Anode loses mass:
e- are donated by metal
ions dissolve in solution – (s) into (aq)
Eventually, anode is completely oxidized to ions
electrons move from anode to cathode ("A to C")
Anode loses mass:
e- are donated by metal
ions dissolve in solution – (s) into (aq)
anode slowly “used up”
Cathode gains in mass:
e- are accepted by cations
cations are reduced – (aq) into (s)
“Plate out” onto the cathode

8. You will have to completely label a diagram like this one

9. Salt bridge - maintains charge balance
filled with an electrolyte solution (salt or acid)
allows movement of ions, without mixing cells
neutralizes half-cell products
Ions build-up in both half-cells as the cell operates – if a cell solution gets too + or – electrons will stop moving through

10. The excess positive and negative ions in the solution are neutralized by the salt bridge ions allowing the redox reaction to continue

11. 2 Ag+(aq) + Cu(s) → 2 Ag(s) + Cu2+(aq)
Line notation
a short hand notation of a voltaic cell.
2 Ag+(aq) + Cu(s) → 2 Ag(s) + Cu2+(aq)

12. An electrochemical cell with Cu (II) oxidizing Zn is constructed.
Identify the anode and cathode.
Write the net equation for the reaction.
What direction do the electrons move?
What is the line notation?

13. Zn(s) + Cu2+(aq) → Zn2+(aq) + Cu(s)
1. Copper is the cathode – reduction.
Zinc is the anode – oxidation.
2. Oxidation: Zn(s) → Zn2+(aq) + 2 e–
Reduction: Cu2+(aq) + 2 e– → Cu(s)
Zn(s) + Cu2+(aq) → Zn2+(aq) + Cu(s)
3. e- move from zinc half-cell to copper half-cell.
4. Zn(s) / Zn2+(aq) // Cu2+(aq) / Cu(s)

14. CAN YOU / HAVE YOU?
Explain the operation of a voltaic (galvanic) cell at the visual, particulate and symbolic level
Include: writing half-cell reactions and overall reaction
Additional KEY Terms
line notation anode cathode
salt bridge