Beginner Topic 644 of 1102 Inorganic Chemistry
Carbon Oxides
Carbon monoxide is toxic and CO2 is a greenhouse gas formed in combustion and respiration.
In-depth explanation of Carbon Oxides
Carbon forms two common oxides with very different properties. Carbon monoxide, CO, is a colourless, odourless gas formed when carbon burns with limited oxygen, and it binds haemoglobin roughly 200 times more strongly than oxygen does. Carbon dioxide, CO2, is a linear, nonpolar molecule produced by complete combustion and respiration. It dissolves in water to form carbonic acid, H2CO3, which gives natural waters their slight acidity. CO2 absorbs infrared radiation and is a major greenhouse gas. Solid CO2, dry ice, sublimes at -78.5 degrees C at atmospheric pressure.
Going deeper: Carbon Oxides
Key ideas: CO is a colorless, toxic gas that binds hemoglobin about 200 times more strongly than O2; it is formed in incomplete combustion and is a reducing agent (blast furnace, Fe2O3 + 3CO gives 2Fe + 3CO2). CO2 is linear and nonpolar, solid form is dry ice (sublimes at -78 C), and it dissolves to give weakly acidic H2CO3 with pKa1 near 6.4. CO has formal triple bond and acts as a ligand.
Common mistakes and connections: Students believe CO2 is the poisonous one or that CO is acidic; CO is neutral oxide. CO2 is a nonpolar molecule despite polar bonds, because the dipoles cancel. Carbonic acid exists mostly as dissolved CO2, so effective pKa is lower than the pure value. Links to carbon monoxide poisoning, metal carbonyls and carbon cycle.
Visualization of Carbon Oxides
Linear, nonpolar CO2 from complete combustion; CO, formed with limited oxygen, binds haemoglobin about 200 times more strongly than O2. The interactive lesson shows this as a live animation or chart.
Worked example and use case
Incomplete combustion of fuel in a poorly ventilated room produces dangerous levels of carbon monoxide.
Frequently asked questions about Carbon Oxides
What is Carbon Oxides?
Carbon monoxide is toxic and CO2 is a greenhouse gas formed in combustion and respiration.
Is Carbon Oxides a beginner, intermediate or advanced topic?
Carbon Oxides is a beginner topic in Inorganic Chemistry. It needs no earlier chemistry lessons and is a good starting point.
What should I learn before Carbon Oxides?
Study these earlier topics in Inorganic Chemistry first: Silicates, Silicones, Glass.
What comes after Carbon Oxides?
The next topics in Inorganic Chemistry are Carbides and Nitrogen Family.
Can I practise Carbon Oxides with quizzes?
Yes. The interactive lesson includes a self-check question on Carbon Oxides, and the Inorganic Chemistry quiz draws on every topic in this area.
Where Carbon Oxides fits in Inorganic Chemistry
Carbon Oxides is topic 29 of 113 in Inorganic Chemistry.