Carbon dioxide (chemical formula CO2) is an acidic colorless gas with a density about 53% higher than that of dry air. Carbon dioxide molecules consist of a carbon atom covalently double bonded to two oxygen atoms. It occurs naturally in Earth's atmosphere as a trace gas. The current concentration is about 0.04% (412 ppm) by volume, having risen from pre-industrial levels of 280 ppm. Natural sources include volcanoes, hot springs and geysers, and it is freed from carbonate rocks by dissolution in water and acids. Because carbon dioxide is soluble in water, it occurs naturally in groundwater, rivers and lakes, ice caps, glaciers and seawater. It is present in deposits of petroleum and natural gas. Carbon dioxide has a sharp and acidic odor and generates the taste of soda water in the mouth. However, at normally encountered concentrations it is odorless.As the source of available carbon in the carbon cycle, atmospheric carbon dioxide is the primary carbon source for life on Earth and its concentration in Earth's pre-industrial atmosphere since late in the Precambrian has been regulated by photosynthetic organisms and geological phenomena. Plants, algae and cyanobacteria use light energy to photosynthesize carbohydrate from carbon dioxide and water, with oxygen produced as a waste product. CO2 is produced by all aerobic organisms when they metabolize organic compounds to produce energy by respiration. For instance, plants use it to produce carbohydrates in a process called photosynthesis. Since humans and animals depend on plants for food, photosynthesis, and therefore CO2, is necessary for the survival of life on earth.
It is returned to water via the gills of fish and to the air via the lungs of air-breathing land animals, including humans. Carbon dioxide is produced during the processes of decay of organic materials and the fermentation of sugars in bread, beer and wine making. It is produced by combustion of wood, peat and other organic materials and fossil fuels such as coal, petroleum and natural gas. It is an unwanted byproduct in many large scale oxidation processes, for example, in the production of acrylic acid (over 5 million tons/year).It is a versatile industrial material, used, for example, as an inert gas in welding and fire extinguishers, as a pressurizing gas in air guns and oil recovery, as a chemical feedstock and as a supercritical fluid solvent in decaffeination of coffee and supercritical drying. It is added to drinking water and carbonated beverages including beer and sparkling wine to add effervescence. The frozen solid form of CO2, known as dry ice is used as a refrigerant and as an abrasive in dry-ice blasting. It is a feedstock for the synthesis of fuels and chemicals.Carbon dioxide is the most significant long-lived greenhouse gas in Earth's atmosphere. Since the Industrial Revolution anthropogenic emissions – primarily from use of fossil fuels and deforestation – have rapidly increased its concentration in the atmosphere, leading to global warming. Carbon dioxide also causes ocean acidification because it dissolves in water to form carbonic acid.
I watched a program on some public broadcast channel where a professor from a university detailed the possible ends of the earth.
One of them (from what I recall) had to do with lowering CO2 levels in the distant future. The lack of CO2 would eventually kill off all plant life.
I tried...
Hey. This probably seems like a bit of an odd question, but which do you suppose would weigh more? Blood with a somewhat average saturation or oxygen (like that which would be found in a healthy individual), or blood completely devoid of oxygen & saturated with carbon dioxide (as in if...
Which has the most CO2. The Earths Crust or the Earth's atmosphere. I know the atmosphere contains only .035%, but I can find any info on the amount of CO2 in the Earth's crust.
thanks
Nautica
Part of Explorations today dealt with CO2 emissions and the melting southern ice shelf. I have a colleague who argues against placing controls on CO2 emissions because, since CO2 is a naturally occurring gas, there is no way that it can be justifiably called 'harmful'. Since it is 'natural'...
C2H5OH -> CO2
"Carbon is oxidized from an oxidation state of -2 in C2H5OH to +4 in CO2"
Don't the rules for oxidation states say that a monatomic ion is the same as its charge, therefore, C cannot be -2 because -4 (C) + 5 (H) + -1 (OH) yields 0 as a charge?