“The Dumas reaction” experiment
How to obtain methane (the easiest method)
There are no useless experiments in chemistry: every experiment involves phenomena from everyday life in some way or another. Today you’ll find out the simplest method to obtain methane.
Conduct the experiment in a ventilated room, and work in protective glasses, gloves and a mask. Observe safety rules when working with flame and flammable substances.
Warning! Only under adults supervision.
Reagents and equipment:
- sodium acetate (5 g);
- sodium hydroxide (5 g);
- test tube;
- spirit burner;
- cork with gas pipe;
- stand with holder.
This reaction is named after the French chemist Jean-Baptiste Andre Dumas, and is a decarboxylation reaction, i.e. carbon dioxide splits off from an anion of carbonic acid.
When carbonic acids salts fuse with alkalis (for example, with sodium hydroxide), the carbon dioxide molecule splits off from the anionic residue of acid. The carbon chain becomes shorter by one carbon atom, and an alkane is formed. In other words, the decarboxylation of the anionic residue of acid takes place.
In our experiment, sodium acetate (its chain has two carbon atoms) fuses with sodium hydroxide. Methane forms (its chain has one carbon atoms), and the carbon dioxide released reacts with sodium hydroxide, forming sodium carbonate:
СН₃СООН + NaOH → СН₄ ↑+ Na₂CO₃