Chemical Compounds - Oxides of carbon.
Carbon monoxide is produced when graphite (one of the naturally occurring forms of elemental carbon) is heated or burned in a limited amount of oxygen. The reaction of steam with red-hot coke also produces carbon monoxide along with hydrogen gas (H
it is useful as a gaseous fuel. It is also useful as a metallurgical reducing agent because at high temperatures it reduces many metal oxides to the elemental metal. For example, copper(II) oxide, CuO, and iron(III) oxide, Fe
Carbon monoxide is an extremely dangerous poison. Because it is an odourless and tasteless gas, it gives no warning of its presence. It binds to the hemoglobin in blood to form a compound that is so stable that it cannot be broken down by body processes. When the hemoglobin is combined with carbon monoxide, it cannot combine with oxygen; this destroys the ability of hemoglobin to carry essential oxygen to all parts of the body. Suffocation can occur if sufficient amounts of carbon
Carbon dioxide is produced when any form of carbon or almost any carbon compound is burned in an excess of oxygen. Many metal carbonates liberate CO
The fermentation of glucose (a sugar) during the preparation of ethanol, the alcohol found in beverages such as beer and wine, produces large quantities of CO
In the laboratory CO
Carbon dioxide is a colourless and essentially odourless gas that is 1.5 times as dense as air. It is not toxic, although a large concentration could result in suffocation simply by causing a lack of oxygen in the body. All carbonated beverages contain dissolved CO
The Earth's atmosphere contains approximately 0.04 percent carbon dioxide by volume and serves as a huge reservoir of this compound. The carbon dioxide content of the atmosphere has signif-icantly increased in the last several years largely because of the burning of fossil fuels. A so-called greenhouse effect can result from increased carbon dioxide and water vapour in the atmosphere. These gases allow visible light from the Sun to penetrate to the Earth's surface, where it is absorbed and reradiated as infrared radiation. This longer-wavelength radiation is absorbed by the carbon dioxide and water and cannot escape back into space. There is increasing concern that the resulting increased heat in the atmosphere could cause the Earth's average temperature to increase 2° to 3° C over a period of time. This change would have a serious impact on the environment, affecting climate, ocean levels, and agriculture. The solubility of carbon dioxide in water makes oceans and lakes significant sources of this gas. Atmospheric carbon dioxide is in dynamic equilibrium with that dissolved in water and with that bound primarily as carbonate in the Earth's crust. With sunlight and chlorophyll serving as a catalyst (i.e., a compound that increases the rate of a reaction without being
Conversely, carbon dioxide is a product of respiration and is returned to the air by plants and animals.
Carbon suboxide, C