. .
3. Zinc and copper in a Galvanic Cell made of two half cells II (wellplate 6)
    see microscalingBradleyE.html

Material
Tray, wellplate 6, 1 lid, 2 plastic pipette tips, 2 plastic pipettes, scissors, nail (10 cm), micro spirit burner, cotton wool, digital multimeter Voltcraft VC333, red and blue wire with crocodile clips,zinc wire, copper wire, 1M 1M solutions of copper sulfate, zinc sulfate, potassium chloride.

Experiment
1. Close well 6 with a lid, heat the nail, weld two holes into the lid
2. The holes must fit to the pipette tips like seen in the left photo.
3. Shorten the upper side of the tips and close their thin ends by a tiny piece of cotton wool.
4. Add 3 mL 1M KCl into well 6 (saltbridge for the two half cells in the tips), close the well.
5. Push the pipette tips into the holes of the lids. The tips must dip into the KClsolution.
6. Design a Zn/Zn²⁺ half cell and a Cu/Cu²⁺ half cell inside the left and the right tip:
    Add 1M ZnSO4 and CuSO4 solution and dip the Zn and the Cu wire into the solutions of their salts (photo 1).
7. Connect the two wires with the multimeter, read the potential (photo 2).

Observation 
The multimeter shows a potential of 1.06 V between Zn (anode) and the Cu half cell (cathode).

Explanation (photo 3)
As an electron donor zinc pushes electrons through the wire to the copper electrode. Zn ions are dissolved.
The copper ions are reduced:   Zn(s) + Cu²⁺(aq) ----indirect redox reaction---> Zn²⁺(aq) + Cu(s)
Negative sulfate ions are flowing to the zinc half cell via well 6.
The standard rduction potentials of the two half-reactions  Zn --> Zn²⁺ + 2e-        Cu²⁺ + 2e- --> Cu   are
- 0.76 V  and + 0.34 V = 1.1 V.