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3B Scientific Electrochemistry Kit User Manual

Page 10

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11

Experiment 2 - Measuring voltage Student instructions

Measuring the voltage of a Daniell cell

Chemicals Hazard

symbols

R phrases

S phrases Equipment

Meter

Copper (II)-sulfate-(5 H

2

O)

22-36/38-50/53 22-60-61 Electrodes:

1 Cu, 1 Zn

Zinc sulfate-(7H

2

O)

36/38-50/53 22-25-60-61

2 Experiment cables

Distilled water

---

---

2 Pipettes


Warning:
Please take care: Salts of heavy metals are poisonous!

Experiment procedure:

1. The prepared 0.1 molar electrolyte solutions should be given to the students. Students require no more than 10 ml of

the relevant solution each.

2. Assemble the battery block as described.
3. Fill one chamber each with electrolyte using the pipette (included in the case). Clean the pipette thoroughly before

using it add the next electrolyte.

4. Insert the appropriate electrodes into the electrolyte solutions, CuSO

4

/ Cu and ZnSO

4

/ Zn.

5. After the chambers have been prepared for the experiment as described, connect the experiment cables to the

meter and start measuring voltages. If a negative voltage is displayed, reverse the polarity of the two electrode
connections.

6. The experiment can also be repeated using 1.0 molar copper sulfate and zinc sulfate solutions.


Observation and evaluation:

Sketch of experiment set-up:














Results of voltage measurement:


1. Daniell cell with 1.0 molar solutions CuSO

4

/ Cu and ZnSO

4

/ Zn:


V


2. Daniell cell with 0.1 molar solutions CuSO

4

/ Cu and ZnSO

4

/ Zn:

V