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The Properties of Carbon Dioxide



The chemical formula for carbon dioxide is CO2 and it appears as a colourless gas. Carbon dioxide was first called “The Gas Sylvester”. “Sylvester” comes from a Latin word which means “woods” or “forest” because the gas was found in caves that had rotting wood. The carbon dioxide formed a layer on the floor in caves. Since no wind was there to blow it away it stayed near the ground. Carbon dioxide is an airy gas made up of one carbon atom and two oxygen atoms. The melting point of carbon dioxide is 216 K (Kelvin) or 57°C. The boiling point is 195K or 78°C. The density of carbon dioxide in solid form is 1.6 x 103 kg/m3 and in gas form at 298 K is 1.98 kg/m3.
USES: You can use carbon dioxide to produce drinks such a soft drinks and soda water. The carbonation in beer and sparkling wine comes through fermentation, although some manufacturers carbonate the drinks artificially. Liquid carbon dioxide is a decent solvent for many organic compounds. It has been attracting pharmaceutical and other chemical processing industries as a less toxic alternative to greater traditional solvents, for example, organochlorides. Carbon dioxide finds uses as a refrigerant, in drink carbonation, and in fire extinguishers. 10.89 billion pounds of carbon dioxide were made by the chemical industry in 1995, and it was ranked 22nd on the list of top chemicals produced in the United States. Because the attention of carbon dioxide in the atmosphere is very modest, it’s not practical to get the gas by removing it from the air. Most industry carbon dioxide is recovered as an outgrowth of other processes. For example, there is the product of ethanol by fermentation and the manufacture of ammonia.
BIOLOGY: Carbon dioxide is a water product in an organism that gains energy by breaking down sugars or fats with oxygen as part of the metabolism, which is in a process known as cellular respiration. This includes all plants, animals, many fungi and only some bacteria. In higher animals, the carbon dioxide flows in the blood, where most of it is held in solution, from the animal’s body tissues to the lungs, where it is exhaled. Plants get rid of carbon dioxide from the atmosphere by photosynthesis, which uses light energy to make organic plant materials by blending carbon dioxide and water. This process releases free oxygen gas. At times, carbon dioxide gas is pumped into greenhouses to increase plant growth. Plants also give off CO2 during respiration; but on balance, they are net sinks of CO2.
ATMOSPHERE: The earth’s atmosphere is about 0.038% CO2 by volume. Due to the greater land area, and therefore, greater plant life in the northern hemisphere as related to the southern hemisphere, there is an annual vibration of about 5 ppm, peaking in May, and reaching a minimum in October at the end of the northern hemisphere, growing season, when the value of biomass on the planet is major. CO2 is a very important element of the Earth’s atmosphere because it absorbs infrared radiation and improves the greenhouse effect. Global warming hypothesis predicts that bigger amounts of CO2 in the atmosphere tend to improve the greenhouse effect and therefore it helps global warming, which isn’t good because the whole world will come to an end.
OCEANS: The Earth’s oceans have a gigantic amount of carbon dioxide in the form of bicarbonate and carbonate ions which are a lot more than the amount in the atmosphere. The bicarbonate is made in reactions between rock, water, and carbon dioxide. The large majority of CO2 added on to the atmosphere will, one day, be absorbed by oceans and become bicarbonate ion, except the process takes about one hundred years because most ocean water would not go near the surface very often. Carbon dioxide is released into our atmosphere when carbon-containing fossil fuels such as coal, oil and natural gas are being burned. The result of the colossal world-wide consumption, a tubercular disease, of those fossil fuels, the amount of CO2 has increased in the atmosphere in the past century and right now it is rising at a rate of 1 ppm per year. Big changes could happen in global climate from a continued increase of CO2 concentration. A new use for liquid CO2 presently under development is a dry-cleaning solvent. Nowadays, many laundries use the chlorinate hydrocarbons as the dry-cleaning solvents. These chlorinated hydrocarbons are likely human carcinogens, so the hunt is on for a switch. CO2 does not exist in the liquid form at any temperature at atmosphere pressure. The temperature pressure stage diagram of CO2 shows that carbon dioxide at liquid state at 20°C needs a pressure of 30 atmospheres! The lowest pressure of liquid CO2 that exists is at the triple point, that is 5.11 atm at -56.6°C. The high pressures required for CO2 need specialized washing machines. Liquid carbon dioxide is a solvent that effects grease and oils, like chlorinated hydrocarbons. Temperatures below -78°C, carbon dioxide CO2 , condenses into dry ice which is a white solid. Liquid carbon dioxide forms at pressures above 5.1 atm at atmosphere pressure, it passes directly through between the gaseous and solid states in a process called sublimation. Water absorbs its own volume of carbon dioxide, and greater that this under pressure. Approximately 1% of dissolved carbon dioxide evolves into carbonic acid. The carbonic acid partly separates to form bicarbonate and carbonate ions.
Safety Warning (for carbon dioxide):
Ingestion- May cause nausea, vomiting, or GI hemorrhaging. Inhalation- It can cause suffocating and hyperventilation. Skin- Dry ice, the solid form of carbon dioxide, may cause frostbite. Eyes- The carbon dioxide can be dangerous. If you are exposed to carbon dioxide a second time it will be very dangerous.
Remember that carbon dioxide can be good because it is used in drinks that taste good even though it is bad for your health, and it can be bad because it helps global warming. What you can do to help is stay alert and stay safe.

References: 1. See For Yourself More Than 100 Experiments For Science Fairs And Projects 2. http://scifun.chem.wisc.edu/chemweek/CO2/CO2.html 3. http://en.wikipedia.org/wiki/Carbon_dioxide




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