Carbon monoxide
Carbon monoxide, with the chemical formula CO, is a colorless, odorless, and tasteless gas. It consists of one carbon atom covalently bonded to one oxygen atom. It is made when carbon compounds burn and there is not enough oxygen. It is a good fuel and burns in air with a blue flame, making carbon dioxide. It is very toxic, but it is useful for modern technology as well.
| Carbon monoxide | |
|---|---|
 |
 |
| |
Carbon monoxide | |
| Other names | Carbon monooxide Carbonous oxide Carbon(II) oxide Carbonyl Flue gas Monoxide |
| Identifiers | |
| CAS number | |
| PubChem | |
| EC number | 211-128-3 |
| KEGG | D09706 |
| MeSH | |
| ChEBI | CHEBI:17245 |
| RTECS number | FG3500000 |
| SMILES | [C-]#[O+] |
| Beilstein Reference | 3587264 |
| Gmelin Reference | 421 |
| Properties | |
| Molecular formula | CO |
| Molar mass | 28.010 g/mol |
| Appearance | colorless gas |
| Odor | odorless |
| Density | 789 kg/m3, liquid 1.250 kg/m3 at 0 °C, 1 atm 1.145 kg/m3 at 25 °C, 1 atm |
| Melting point |
−205.02 °C, 68 K, -337 °F |
| Boiling point | |
| Solubility in water | 27.6 mg/L (25 °C) |
| Solubility | soluble in chloroform, acetic acid, ethyl acetate, ethanol, ammonium hydroxide, benzene |
| kH | 1.04 atm·m3/mol |
| −9.8·10−6 cm3/mol | |
| Refractive index (nD) | 1.0003364 |
| Dipole moment | 0.122 D |
| Thermochemistry | |
| Std enthalpy of formation ΔfH |
−110.5 kJ/mol |
| Std enthalpy of combustion ΔcH |
−283.4 kJ/mol |
| Standard molar entropy S |
197.7 J/(mol·K) |
| Specific heat capacity, C | 29.1 J/(K·mol) |
| Hazards | |
| EU classification |  F+  T+
|
| NFPA 704 |
4
3
0
|
| R-phrases | R61 R12 R26 R48/23 |
| S-phrases | S53 S45 |
| Explosive limits | 12.5–74.2% |
| U.S. Permissible exposure limit (PEL) |
TWA 50 ppm (55 mg/m3) |
| Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa) | |
The most important use for carbon monoxide in industry is making iron from iron ore. The carbon monoxide takes the oxygen from the iron ore when heated in a large oven called a blast furnace. Liquid metal iron is left behind. The carbon monoxide turns into carbon dioxide.
Carbon monoxide can accidentally form when there is too little air to burn all the fuel into carbon dioxide. Such a situation may happen if the oven shutters are closed too early or if a mobile cooker is used in a small tent with no ventilation (Ventilation is fresh air coming in and smoke going out). Many people have died from carbon monoxide poisoning. Low-level carbon monoxide poisoning can cause feelings of paranoia and hallucinations, and has been determined to be a major cause of "haunted" houses. Higher levels of carbon monoxide can cause flu-like symptoms, headaches, and death. Small amounts of it are found in coal gas, a fuel produced by heating coal without any air.
Production
Despite that it is a poison, carbon monoxide is very useful in chemical industry so lots of ways of making it have been discovered.[2] Normally we burn coke at high temperature with not enough oxygen. Blast furnaces work this way. The chemical equation for this is:
- 2C + O2 → 2CO
It can be also made by blowing hot steam through red-hot crushed coke
- C + H2O → CO + H2
Carbon monoxide can be used as heating fuel because it burns easily into carbon dioxide. It can also be used as so-called "synthesis gas" for making man-made gasoline in the Fischer-Tropsch process.
During the World War II when petrol was rare and reserved for the military, many cars were converted to use wood gas. It is carbon monoxide made by burning wood chips in insufficient amount of air. The wood gas was made in a special oven called generator, which was carried on the car. The resulting carbon monoxide was then used as fuel for the car itself. Even today there are cars which use wood gas as fuel.
Carbon Monoxide Media
The most important resonance form of carbon monoxide is –C≡O+. An important minor resonance contributor is the non-octet carbenic structure :C=O.
Monthly averages of global concentrations of tropospheric carbon monoxide at an altitude of about 12,000 feet. Data were collected by the MOPITT (Measurements Of Pollution In The Troposphere) sensor on NASA's Terra satellite.
The streak of red, orange, and yellow across South America, Africa, and the Atlantic Ocean in this animation points to high levels of carbon monoxide on September 30, 2005.
Carbon monoxide concentrations in Northern Hemisphere spring as measured with the MOPITT instrument
Energy level scheme of the σ and π orbitals of carbon monoxide
Structure of iron pentacarbonyl.
- IronpentacarbonylDballs
References
- ↑ GOV, NOAA Office of Response and Restoration, US. "CARBON MONOXIDE - CAMEO Chemicals - NOAA". cameochemicals.noaa.gov.
- ↑ Holleman, A. F.; Wiberg, E. "Inorganic Chemistry" Academic Press: San Diego, 2001. ISBN 0-12-352651-5.
Other websites
- International Chemical Safety Card 0023
- National Pollutant Inventory - Carbon Monoxide Archived 2009-02-08 at the Wayback Machine
- NIOSH Pocket Guide to Chemical Hazards
- United States Environmental Protection Agency Carbon Monoxide page
- External MSDS data sheet Archived 2006-05-16 at the Wayback Machine
- Carbon Monoxide Kills Campaign Site Archived 2007-04-18 at the Wayback Machine
- Carbon Monoxide information for victims of poisoning
- Carbon Monoxide Hazards with Backpacking Stoves
- USFDA IMPORT BULLETIN 16B-95, May 1999 Archived 2012-07-16 at the Wayback Machine
- FDA Agency Response Letter GRAS Notice No. GRN 000083 Archived 2007-04-11 at the Wayback Machine
- Carbon Monoxide in Fresh Meat site Archived 2007-03-25 at the Wayback Machine
- Radiology and Pathology of CO Poisoning[dead link] Images from MedPix