3B Scientific Electrochemistry Kit User Manual
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Experiment 8 - Measuring voltage Student instructions
Measuring the voltage for various electrolyte concentrations
Chemicals Hazard
symbols
R phrases
S phrases
Equipment
Meter
Silver nitrate
34-50/53 26-45-60-61
Electrodes:
2 Ag
Distilled water
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2 Experiment cables
2
Pipettes
Warning: Be careful when handling silver nitrate! Silver nitrate is corrosive!
Experiment procedure:
1. Silver nitrate solutions of various concentrations should be given to the students.
2. Assemble the battery block as described.
3. Fill two chambers located opposite one another in the battery block with 0.1 molar silver nitrate solution and insert a
silver electrode into both of them.
4. Fill two more chambers with 1 molar and 0.01 molar silver nitrate solution.
5. First measure the voltage for the Ag / AgNO
3
(0.1 mol/l) //Ag / AgNO
3
(0.1 mol/l) cell. Both silver electrodes should
be connected to the meter.
6. Remove one silver electrode from the 0.1 molar silver nitrate solution, rinse thoroughly with water and insert into the
1 molar silver nitrate solution. The voltage produced by the
Ag / AgNO
3
(0.1 mol/l) //Ag / AgNO
3
(1.0 mol/l) cell can now be read off from the meter.
7. Next remove the silver electrode from the 1 molar silver nitrate solution, rinse thoroughly with water again
and insert into the 0.01 molar silver nitrate solution. The voltage produced by the
Ag / AgNO
3
(0.1 mol/l) //Ag / AgNO
3
(0.01 mol/l) cell can now be read off from the meter.
8.
For the next experiment remove the silver electrode from the 0.1 molar silver nitrate solution, rinse thoroughly with
water and insert into the 1.0 molar silver nitrate solution. The voltage from the Ag / AgNO
3
(1.0 mol/l) //Ag / AgNO
3
(0.01 mol/l) cell can now be read off from the meter.
Observation and evaluation:
Sketch of experiment set-up:
Result of voltage measurement:
Galvanic cell
Measured
voltage (V)
Ag / AgNO
3
(0.1 mol/l) // Ag / AgNO
3
(0,1 mol/l)
Ag / AgNO
3
(0.1 mol/l) // Ag / AgNO
3
(1.0 mol/l)
Ag / AgNO
3
(0.1 mol/l) // Ag / AgNO
3
(0.01 mol/l)
Ag / AgNO
3
(0.1 mol/l) // Ag / AgNO
3
(1.0 mol/l)