oxides of Carbon. Of the several oxides of carbon, the most important are carbon monoxide, CO, and carbon dioxide, cabondyoxide. Carbon monoxide is a colorless, odorless gas formed by the incomplete combustion of carbon or carbon-containing compounds: Industrially, CO is prepared by passing steam over heated coke. Carbon monoxide burns readily in oxygen to form carbon dioxide: Carbon monoxide is not an acidic oxide (it differs from carbon dioxide in that regard) and is only slightly soluble in water.