Formic anhydride can be isolated by low-temperature, low-pressure distillation, but decomposes on heating above room temperature. It decomposes into formic acid and carbon monoxide. The decomposition of formic anhydride may be catalyzed by formic acid. Formic anhydride can be detected in the gas-phase reaction of ozone with ethylene. The molecule is planar in the gas phase. Formic anhydride Formic anhydride, also called methanoic anhydride, is an organic compound with the chemical formula and a structural formula of (H(C=O)−)O. It can be viewed as the anhydride of formic acid (HCOOH). Formic anhydride can be obtained by reaction of formyl fluoride with sodium formate
Nitric acid and for this reason it was often stored in brown glass bottles: This reaction may give rise to some non-negligible variations in the vapor pressure above the liquid because the nitrogen oxides produced dissolve partly or completely in the acid. The nitrogen dioxide (NO) remains dissolved in the nitric acid coloring it yellow or even red at higher temperatures. While the pure acid tends to give off white fumes when exposed to air, acid with dissolved nitrogen dioxide gives off reddish-brown vapors, leading to the common name "red fuming acid" or "fuming nitric acid" – the most concentrated form of