Carbon dioxide

Carbon dioxide
General
Systematic name	Methanedione
Other names	Carbon-12 dioxide carbonyl oxide Carbonic acid gas Carbonic acid anhydride Carbonic acid gas Dioxido de carbono [Spanish] dioxidocarbon dioxomethane Dioxyde de carbone [French] Kohlendioxyd [German] methane, dioxo- After-damp dioxidocarbon carbon oxide Carbonica carbonic anhydride Khladon 744 koldioxid kooldioxide 二氧化碳 [Chinese]
Molecular formula	CO2
SMILES	O=C=O
Molar mass	Molar mass::44.0095 g/mol
Appearance	Colorless, odorless
CAS number	CAS number::124-38-9
Properties
Density and phase	[[Density:: gas: 1.98 kg/m³ solid: 1562 kg/m3 liquid: 1032 kg/m3]]
Solubility in water	90 cm3/100 ml (°C)
Melting point	Melting point::-55.6°C
Boiling point	Boiling point:: -78.5°C
Acidity (pKa)	6.35
Viscosity	.07 cP at -78.5°C
Structure
Molecular shape	trigonal planar
Dipole moment	0 D
Hazards
Exposure Limit	Long-term exposure limit (8-hr reference period) of 5000 ppm Short-term exposure limit (15 minute reference period) of 15000 ppm
MSDS	Material safety data sheet
NFPA 704	0 2 0
Flash point	none
R/S statement	R: R 28 32 50/53 S: S 28 45 61
RTECS number	FF6400000
Related compounds
Related compounds	Carbon monoxide Dicarbon monoxide Carbon suboxide Carbonyl sulfide Carbon trioxide Carbonic acid
Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa) Disclaimer and references

Carbon dioxide is an organic oxide. Though not the most prevalent of the earth's gases, influences the world in a profound way. Carbon dioxide makes life on earth possible. Plants use carbon dioxide to make carbohydrates in photosynthesis, which in turn provides energy to animals that eat plants (herbivores) and on through the food chain. Carbon dioxide also finds use in many industrial processes, making modern life possible. The first gas to be discovered, carbon dioxide continues to astound scientists with new discoveries and applications. Carbon dioxide also plays a large role in the environment. Other than keeping both flora and fauna alive, carbon dioxide helps determine the overall temperature of the earth. New research suggests that the cold and warm periods the earth has experienced were in large part due to the amount of carbon dioxide in the atmosphere. This gas stands as a testament to God's complexity in design, illuminating his clever ways through the multitude of uses for this compound.

Properties

Carbon Dioxide, a colorless, odorless gas, makes up about .038% of the atmosphere, this amount, about 380 ppm, has increased steadily for the last sixty years, and continues to increase at a current rate of about 380 ppm a year. Carbon dioxide is a non-combustible compound, and a concentration of air about 10% carbon dioxide will snuff out any flame, as well as any human life in the area. The compound is acidic, and combines with water to produce carbonic acid. Also, due to its acidic qualities, carbon dioxide, if inhaled in large quantities, will produce a sour impression and stinging in nose and through. This material has no liquid stage in room temperature, instead sublimating directly from a solid to a gas. This property has been utilized by food handling companies to keep food cool without dealing with the mess and weight of water. However, carbon dioxide does have some weight, as it is 1.5 times heavier than air, causing it to concentrate at low elevations. Carbon dioxide occurs naturally in the environment, and can be obtained from natural gas wells, organic material, and fossil fuels. This compound is made up of two oxygen atoms surrounding a carbon atom at a 180°, consequently creating a very stable compound, and as a result will not mix with alkali metals. This gas, though deadly in large amounts as it causes asphyxiation in oxygen-breathing life forms, is necessary for life. Plant life, the basis for animal life, consumes carbon dioxide to survive, and utilizes the compound to create sugars, necessary for both the growth of the plant and as a food source for animals. Carbon dioxide can also create a bubbly stimulating sensation in liquid. Pure carbon dioxide demonstrates triple point characteristics, where it can exist as both a liquid, a solid, and a gas at the same time when above 60.4 psi. Liquid carbon dioxide can only occur at pressures above 5.1 atm.

Occurrences

Carbon Dioxide can be found throughout the entire atmosphere, making up an integral part of the air.

Carbon Dioxide, a ready ingredient in the atmosphere, can be found anywhere on earth. If a plant is living there, carbon dioxide will also be found. Carbon Dioxide may also be absorbed into the water or earth, and great quantities of the gas may be stored there. Anything which absorbs a large quantity of Carbon Dioxide is known as a sink. . Carbon dioxide transitions between these mediums through a process known as the Carbon Cycle. This biogeochemical process involves the transition of carbon dioxide from sinks to the atmosphere and vice versa. The Carbon cycle serves to balance the earth's temperature, never allowing all of the earth's carbon dioxide to enter the atmosphere. However, according to current research, only the ocean absorbs more carbon dioxide than it gives off, absorbing about 2.5 gigatons of carbon per year. The forests of the Northern Hemisphere may also absorb carbon dioxide, though data regarding this claim is still new and uncertain. Each factor in this process is intertwined, and CO2 production, land sinks, ocean sinks, and vegetation sinks all affect each other in surprising ways. Naturally occurring carbon dioxide takes the form of a gas, though through artificial means the compound may be frozen or liquefied.

Uses

Commercial Uses

Carbon Dioxide has many commercial uses. It is used to decaffeinate coffee. In creating perfumes, carbon dioxide can easily purify and separate volatile fragrances . The gas can also separate and purify flavors from hops, spices, and herbs. Also, as the gas sublimates directly from a solid to a gas, it can provide the cooling factor of ice without the mess of a puddle. Liquid carbon dioxide is also used to keep items at intensely cool temperatures.

Industrial uses

Carbon can purify polymer, animal and vegetable fibers. It controls nuclear reactor temperatures. It carbonates sodas, mineral waters, and several types of beer. In non-ferrous metallurgy, carbon dioxide suppresses fumes during transfer of bullion or matte. It can also increase the efficiency of oil wells by reducing the viscosity of the oil. . Dry ice pellets can replace sandblasting when removing paint. The gas can act as a shield when MIG/MAG wielding, protecting the weld puddle from oxidation from the air. Carbon dioxide makes a very effective fire extinguisher. Increasing the carbon dioxide in the air around plants greatly increases their yield, providing more of a crop.

Scientific Uses

Carbon dioxide was the first gas to be discovered, in 1756. The discovery of this gas opened all sorts of doors in the observation of plant life and the human body. Recently, the study of this gas has greatly increased human understanding of climate change. In the medical world, Carbon creates almost physiologic temperatures for operating artificial organs. As a component with oxygen or air, it can stimulate deep breathing. Also, carbon dioxide based semiconductors have recently been invented.

Climatic impact

Plant growth, especially jungle growth, serves as an invaluable carbon sink, preventing the gas from rising to the atmosphere.

As of late, climate change has been a hot topic in the media and scientific circles. There is no doubt the the earth's climate has been rising, but many question carbon dioxide's place in climate change. Carbon dioxide is a greenhouse gas, meaning it traps heat inside it. However, this classification does not necessarily mean the gas is responsible for global warming, as it makes up a very small portion of the atmosphere. Controversy over the effects of carbon dioxide continued until around the latter half of 2000-2010, and now it has been generally accepted that carbon dioxide does influence climate change, and influences it enough to be a threat. Conclusive evidence of the effectiveness of carbon dioxide at heating the environment was determined in 2005, when a study determined that the net heat of the ocean was increasing by one watt per square meter, and that overall the planets heat-energy was rising. This meant that the earth was taking in more heat from the sun than it was releasing. As Tim Barnett writes, "The number was just what the elaborate greenhouse effect computations had been predicting for decades. James Hansen, leader of one of the studies, called the visible increase of the planet's heat content a 'smoking gun' proof of greenhouse effect warming (see graph below). Moreover, in each separate ocean basin there was a close match between the pattern of rising temperatures measured at each location and depth and detailed model calculations of where the greenhouse effect warming should appear. Warming from other sources, for example a change in the Sun's output, could not produce these patterns. Evidently the modelers were on the right track."

The results of these studies have by no means predicted a wasteland or worldwide desert. Rather, these findings point toward a gradual hastening of the cyclic return to the higher temperatures the earth experienced in the past. However, even a moderate change in global temperature will result in an increase of sea level which will displace millions. The effects of carbon dioxide have led to intense controversy over how to curb the rapid production of this gas. However, the production of carbon dioxide stems largely from necessary activities, such as the production of electricity and operation of automobiles. . The United States has considered several deterrents to the production of greenhouse gasses, including cap and trade bills as well as carbon taxes. These taxes have not been implemented on a federal level, but rather on a state and city level, with more than ten states implementing cap and trade laws and Los Angeles and Boulder implementing small carbon taxes. However, these taxes can be detrimental to industry, and if other countries, particularly China, do not follow suit with their own greenhouse policies, the United States may soon find itself at an economic disadvantage.

Video

The basics of carbon dioxide