Apparatus for Water Electrolysis (Hoffman Voltmeter)
Product Code : SCL-CL-11449
Apparatus for Water Electrolysis (Hoffman Voltmeter) (SKU SCL-CL-11449), better known as the Hofmann voltameter, splits acidified water into hydrogen and oxygen and collects each gas in its own graduated tube so the volumes can be compared. It is a standard demonstration in school chemistry and physics and in college electrochemistry. Science Lab Supplies offers the apparatus from Ambala, India to schools, colleges, training institutes, distributors and tender buyers.
Specifications
The voltameter stands 600 mm high and is made of three glass tubes: two graduated 25 ml gas-collecting tubes, each closed by a ground glass tap, and a third tube used for filling. Carbon and carbon-platinum electrodes sit at the base of the collecting tubes and connect through conducting wires.
| Parameter | Value |
|---|---|
| SKU | SCL-CL-11449 |
| Also known as | Hofmann voltameter, water electrolysis apparatus |
| Tubes | 3 glass tubes: 2 graduated, 1 filling tube |
| Graduated tube capacity | 25 ml each, 1 mm graduations |
| Height | 600 mm |
| Electrodes | Carbon and carbon-platinum |
| Taps | Ground glass |
| Supplied by | Science Lab Supplies, Ambala, India |
Applications and Experiments for the Hofmann Voltameter
The apparatus is used to show that water decomposes into two volumes of hydrogen for every volume of oxygen when a direct current passes through it. It serves decomposition-reaction lessons in secondary school and electrochemistry practicals in senior classes and undergraduate courses.
- NCERT Class 10 science: electrolysis of water as a decomposition reaction.
- NCERT Class 8 science: chemical effects of electric current.
- Class 12 chemistry and B.Sc. practicals: electrolysis and Faraday's laws.
- Gas tests: releasing each gas through its tap for the burning-splint and glowing-splint tests.
Hydrogen is flammable, so gas tests should be done in small amounts under teacher supervision, away from open flames, and acid electrolytes need gloves and eye protection.
Standard Scope of Supply
The set consists of the three glass tubes (two graduated 25 ml tubes with ground glass taps and one filling tube), carbon and carbon-platinum electrodes and electrical conducting wires. The listing names no DC power supply, stand or electrolyte, so add any of these you need to the quotation.
Packing, MOQ and Lead Time
Whether you need one voltameter for the teacher's bench or several for a school chemistry lab equipment order, ask for a quotation for that quantity. It will state the packing, the delivery time and the price, and a stand or spare electrodes can be quoted on the same sheet.
Holding an Importer-Exporter Code as a registered exporter, Science Lab Supplies can ship to buyers in the Philippines, Nepal, Bangladesh, Zambia, Rwanda and South Africa. Reach us through the contact page or build a list in the enquiry cart; tender buyers can also see the lab tender page.
Frequently Asked Questions
Is this a voltmeter?
No. The product name says voltmeter, but the apparatus is a Hofmann voltameter, an electrolysis cell that collects gases. It does not measure voltage.
Why does one tube collect twice as much gas?
Water contains two hydrogen atoms for each oxygen atom, so electrolysis gives twice the volume of hydrogen at the cathode as oxygen at the anode. The 25 ml graduated tubes let students read both volumes.
Who supplies the Apparatus for Water Electrolysis (Hoffman Voltmeter)?
It is supplied by Science Lab Supplies from Ambala, India. Schools and colleges can order it directly, and distributors and tender contractors can ask for quantity quotations.
Is a stand included?
The listing does not include a stand. A separate Hofmann voltameter stand is available in the same range and can be added to your quotation.
Related Electrolysis Apparatus
These four items belong with the voltameter on an electrochemistry bench: a stand to hold it upright, spare platinum electrodes, a U-tube cell for electrolysing salt solutions, and a eudiometer for recombining hydrogen and oxygen into water. Each can go on the same enquiry.
- Hoffman Voltameter Stand — holds the voltameter upright.
- Electrode Rod Platinum — spare electrode for electrolysis cells.
- Apparatus for the Electrolysis of Salts — U-tube cell for salt solutions.
- Apparatus for Water Synthesis (Eudiometer) — the reverse experiment, forming water from its gases.
Browse the full Chemistry Lab range or all school lab equipment.
Last updated: 25 September 2026
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