3B Scientific Hoffmann Electrolysis Apparatus - Manual

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Instruction sheet
3B SCIENTIFIC 3B SCIENTIFIC 3B SCIENTIFIC 3B SCIENTIFIC 3B SCIENTIFIC® PHYSICS PHYSICS PHYSICS PHYSICS PHYSICS
®
The purpose of the water-decomposition is for the elec-
trolysis of water (converting electrical energy into
chemical energy), quantitative determination of the
resulting gases and confirmation of Faraday’s laws.
1. Safety instructions
•
Since the conductivity of distilled water is too low,
electrolysis is carried out using dilute sulfuric acid
(c =1 mol/l approx.).
•
Carefully add the sulfuric acid to the water while
stirring. Never do this the other way round.
•
Wear protective goggles when mixing the solution
and when releasing the gases.
•
Students should always be informed of the dan-
gers of the chemicals needed for the experiment.
•
Caution. Any acid that escapes can cause irrepa-
rable stains and holes in clothing.
•
Be careful when taking the glass tubing off its se-
curing plate.
•
Do not subject the glass components of the water-
decomposition apparatus to mechanical stress.
2. Description, technical data
The water-decomposition apparatus consists of an H-
shaped section of glass tubing attached to a securing
plate fixed to a stand rod that rests on a base-plate.
The glass section involves two gas collection tubes each
U14332 Hofmann water-decomposition apparatus
11/03 ALF
with a measuring scale. At the top of each tube there
is a ground stopcock. Two platinum electrodes are se-
cured at the lower ends via GL-18 screw fittings. A flex-
ible plastic hose leads to a leveling bulb for equalising
the pressure in the collection tubes.
Dimensions:
Water-decomposition apparatus:
Height: 800 mm approx.
Width: 150 mm
Base-plate: 250 mm x 160 mm
Rod: 750 mm x 12 mm Ø
Securing plate: 120 mm x 110 mm
Gas collection tubes:
Height: 510 mm
Width: 150 mm
Tube diameter: 19 mm
Scale: 50 ml each with 0.2 ml divisions
Leveling bulb:
Volume: 250 ml
2.1 Scope of delivery:
1 Glass section with gas collection tubes
1 Base-plate with stand rod and securing plate
1 Pair of platinum electrodes with 4-mm sockets
1 Leveling bulb with plastic hose
1 Stand ring to hold the leveling bulb
1 Universal sleeve
1 Base-plate with stand rod
2 Platinum electrodes
3 GL-18 screw fitting
4 GL-14 screw fitting
5 Gas collection tubes
6 Securing plate
7 Ground stopcock
8 Plastic hose
9 Stand ring
bl Leveling bulb
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