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 sends it out from its base in Ambala, India, with quotations prepared for schools, colleges, institutes, distributors and tender buyers alike.
Specifications
The table gives every specification of this 600 mm Hofmann voltameter. In short, it 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, with carbon and carbon-platinum electrodes connected through conducting wires.
| Specification | Value |
|---|---|
| SKU | SCL-CL-11449 |
| Also known as | Hofmann voltameter, water electrolysis apparatus |
| Number of glass tubes | 3 |
| Graduated tubes | 2 |
| Third tube | Filling tube |
| Graduated tube capacity | 25 ml each |
| Graduation | 1 mm |
| Height | 600 mm |
| Electrodes | Carbon and carbon-platinum |
| Taps | Ground glass |
| Connections | Electrical conducting wires |
| 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; a simpler test-tube version uses the stainless-steel Electrolysis Kit.
- Class 12 chemistry and B.Sc. practicals: electrolysis and Faraday's laws, with a spare Electrode Rod Carbon Voltameter for worn carbon electrodes.
- Gas tests: releasing each gas through its tap for the burning-splint and glowing-splint tests with Wood Splints.
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. A DC power supply, stand and electrolyte are not included; 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. Name the number of voltameters you need in a message from the contact page or a list in the enquiry cart; school boards issuing a tender will find the process on 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 the gases formed from water. It does not measure voltage and has no meter scale.
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)?
Orders are handled by Science Lab Supplies, an Ambala, India business that sources this voltameter for schools and colleges directly and prepares quantity quotations for distributors and tender contractors.
Is a stand included?
No stand comes with the glass unit. The Hoffman Voltameter Stand from the same range, a metal stand with support clamp on a 600 mm rod, can be added to your quotation.
Related Electrolysis Apparatus
These Chemistry Lab, Electrical and Electronics and Physics Lab items hold, equip or offer alternatives to a water voltameter, including other voltameter designs, electrodes and the reverse water-synthesis experiment, and each can go on the same enquiry.
- Hoffman Voltameter Stand — metal stand and support clamp, supplied with a 600 mm rod.
- Electrode Rod Platinum — platinum-leaf electrode for electrochemistry experiments, mounted in a glass tube with a terminal.
- Hoffman Voltameter With Electrodes — limbs graduated 2–50 ml, with 2 carbon and 2 platinum electrodes; needs a 12 V supply.
- Hoffman Voltameter — limbs graduated 50 x 0.2 ml with stopcocks and removable carbon electrodes.
- Voltameter — base-mounted with terminals, platinum electrodes and two 10 ml graduated test tubes.
- Electrolysis Apparatus — titanium electrodes in a rubber stopper, 4 mm safety sockets and two 18 x 180 mm graduated tubes.
- Apparatus for Water Synthesis (Eudiometer) — 16 mm resistant-glass tube, closed at one end, with a conductor filament.
Browse the full Chemistry Lab range, the Electrical and Electronics range, or all school lab equipment.
Last updated: 9 October 2026
