Formic acid

Formic acid, or methanoic acid, is a carboxylic acid derived from methanol. Naturally it occurs in ant venom and various stinging nettles. It was first synthesized by French chemist Joseph Gay-Lussac using hydrogen cyanide. It's commonly prepared in the lab via the reaction of oxalic acid with glycerol. I used this method myself:


I started with 30ml of glycerol in a beaker. Under the beaker I placed a hotplate, which I turned to high heat to drive off all the water. It's important that water is kept to a minimum as it will lower the quality of the final product. Anyway, to the glycerol I added 24g of hydrated oxalic acid. I set up for simple distillation and heated the mixture untill it turned dark red. The formic acid distillate collected was placed in a vial for storage. This method produced very concentrated acid. It probably could have been even more concentrated if anhydrous oxalic acid had been used. The reaction can also produce allyl alcohol under certain conditions.

C2H2O4 ==> CH2O2 + CO2