- Carbon monoxide (CO): Carbon monoxide is a colourless, odourless, and poisonous gas. It is produced by the incomplete combustion of hydrocarbons. Carbon monoxide is a reducing agent and readily reacts with oxygen to form carbon dioxide.
- Carbon dioxide (CO2): Carbon dioxide is a colourless, odourless, and non-toxic gas. It is produced by the complete combustion of hydrocarbons. Carbon dioxide is a greenhouse gas and contributes to global warming.
- Carbon suboxide (C3O2): Carbon suboxide is a colourless gas with a pungent odour. It is produced by the dehydration of malonic acid. Carbon suboxide is a reactive molecule and readily polymerizes to form polycarbon suboxide.
- Carbon dioxide dimer (C4O4): Carbon dioxide dimer is a white solid that is stable at room temperature. It is produced by the reaction of carbon monoxide with singlet oxygen. Carbon dioxide dimer is a powerful oxidizing agent and readily decomposes to form carbon dioxide and oxygen.
- Carbon trioxide (CO3): Carbon trioxide is a red-orange solid that is unstable at room temperature. It is produced by the reaction of carbon dioxide with ozone. Carbon trioxide is a powerful oxidizing agent and readily decomposes to form carbon dioxide and oxygen.
