In 1811, Avogadro stated his hypothesis that under the same conditions of pressure and temperature, equal volumes of all gases contain equal numbers of components (molecules, atoms). He derived this from the uniformity of the behaviour of (ideal) gases on increases in temperature and pressure (see the Gas Laws) and the Law of Volumes. When Avogadro's supposition is correct, then 6 parts by volume of CO and 3 parts by volume of O2 must form 6 parts by volume of CO2 when pressure and temperature are the same before and after the reaction. Similarly, at a temperature a little above 100°C, a gas mixture containing 6 parts by volume of H2 and 3 parts by volume of 02 must give 6 parts by volume of steam, and a mixture containing 5 parts by volume of H2 and 5 parts by volume of Cl2 must give 1 0 parts by volume of HCI. In the following experiments we will carry out the reactions named above to test the correctness of the hypothesis.


  • Safe and controlled test procedure by slow eudiometer
  • Practical gas bar for storing the gases
  • Special heater for glass jacket for optimal temperature control


Perform the following reactions to verify Avogadro's law:

  1. Preparation of carbon monoxide and chlorine
  2. The carbon monoxide/oxygen reaction
  3. The hydrogen/oxygen reaction at above 100°C
  4. The hydrogen/chlorine reaction at above 100°C

What you can learn about

  • Avogadro's law
  • Gas laws
  • Carbon monoxide
  • Hydrogen
  • Chlorine
  • Oxygen

Necessary accessories

  • Precision balance 620g/0.001g


Scope of Supply
Device NameItem no.Qty
Retort stand, h = 750 mm37694-001,00
Spoon, special steel33398-001,00
Connecting cord, 30 kV, 1000 mm07367-002,00
Ignition spark generator11155-001,00
Support rod, stainless steel, l = 250 mm, d = 10 mm02031-002,00
Hose clip f.12-20 diameter tube40995-002,00
Lab thermometer,-10..+150C38058-002,00
Round bottom flask, 100ml, GL 25/1235841-151,00
Teclu burner, DIN, natural gas32171-051,00
Plunger eudiometer02611-001,00
Beaker, Borosilicate, tall form, 250 ml46027-001,00
Lab protecting glasses with UV filter39315-001,00
Reducing valve f.oxygen33482-001,00
Formic acid 75% 25030023-251,00
Hydrochloric acid 37 %, 100030214-701,00
Support rod, stainless steel, l = 600 mm, d = 10 mm02037-002,00
Table stand for 2 l steel cylinders41774-002,00
Lighter f.natural/liquified gases38874-001,00
Funnel for gas generator, 50 ml, GL1835854-151,00
Heating apparatus for glass jacket system32246-931,00
Gas syringe, 100 ml02614-001,00
Wrench for steel cylinders40322-001,00
Right angle boss-head clamp37697-003,00
Reducing valve for hydrogen33484-001,00
Sulphuric acid, 95-97%, 500 ml30219-501,00
Syringe 10ml, Luer, 10 pcs02590-031,00
Steel cylinder hydrogen, 2 l, full41775-001,00
Safety gas tubing, DVGW, sold by metre39281-101,00
Graduated beaker with handle, 1000 ml, plastic (PP)36640-001,00
Power regulator32288-931,00
Glass jacket02615-001,00
Support base DEMO02007-551,00
Gas bar40466-002,00
Universal clamp37715-003,00
Funnel, glass, top dia. 50 mm34457-001,00
Water, distilled 5 l31246-811,00
Cannula 0,45x13 mm, Luer, 20 pcs02598-041,00
Steel cylinder oxygen, 2 l, filled41778-001,00
Silicone tubing i.d. 7mm, 1 m39296-002,00
Boiling beads, 200 g36937-201,00
Base plate for support base DEMO02007-011,00

Downloads and Documents

Document  Filesize
11349_01.pdfVersuchsbeschreibung, German402.04 KB
p3111000e.pdfExperiment guide, English488.9 KB