What is Co2: Definition and 307 Discussions

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.

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  1. G

    CO2 Gas cooler in Air conditioning

    Homework Statement Investigation on CO2 gas cooler for Automobile air conditioning system Homework Equations I am trying to design a gas cooler for an automobile air conditioning system using CO2. The Attempt at a Solution I have conducted a literature review and understand the super and...
  2. F

    Lifetime of CO2 in Mars atmosphere

    Homework Statement Estimate the lifetime of CO2 in the atmosphere of Mars. Homework Equations The Attempt at a Solution What is he asking? How long has the CO2 been in the atmosphere? It just seems rather vague.
  3. V

    SI engine combustion. CO2 dissociation?

    Hey guys, Had this over in the mechanical engineering section but I think I might have more luck with getting an answer over here. The question is, what is happening to make the extra power when using a rich mixture in an SI engine? An air fuel ratio (AF:R) of 14.7:1 is stoichiometric for...
  4. M

    How efficient is the process of creating CH4 from excess green energy?

    Creating CH4 from H2 + CO2 This was a topic raised before. However a point that should have been made and wasn't is as follows. The problem with electricity is that it cannot be stored. Wind energy often has to be dumped at times of low demand (night, holiday periods, weekends). The amount and...
  5. R

    I'm trying to figure out how to sequester CO2 from furnace exhaust

    My plan is to burn bio-matter like weeds and wood (or bio-fuel) in a zero-pollution scheme that collects the particulate material, oil, water and CO2 generated from burning the hydrocarbons and uses it for other purposes. It would filter out any toxins or NOx and vent N2. I know that I can...
  6. G

    Solution of NaCl and CO2. Name species and find concentrations of species.

    So, I'm assuming no Sodium Bicarbonate or Carbonate is formed during this process. I found the concentrations of the species by basic ICE diagram. Mostly, I need to know how to approach this problem conceptually . I'm assuming the effect of NaCl on the CO2-->H2CO3-->HCO3- --> CO3--...
  7. H

    Infrared absorption spectrum of CO2 at 4,3 µm

    Hello! I'm writing a thesis about the optical properties of CO2. However I'm having a hard time finding any solid material about the basic info of the absorption spectrum of CO2. I'm especially interested in the absorption band at approximately 4,3µm. If any of you guys know some good articles...
  8. S

    Is it possible to convert methane to carbon dioxide without combustion?

    I would like to convert methane to carbon dioxide without using combustion. The aim is to generate as little heat through the process as possible. Any ideas how this might be achieved would be appreciated. Cheers
  9. T

    Balancing Redox Reactions: CH4 + O2 --> CO2 + H2O

    a. CH4(g) + 2O2(g) ----------> CO2(g) + 2H2O(g) I need to determine which is reduced and which is oxidized, I already know that C in methane is Oxidized. O2 is reduced but how can you determine that?? I know it has to do with electron transfer but I just don't see it
  10. I

    Help needed on calculating system pressure during rapid phase transition of CO2

    Dear Members, I am strugling with calculations on rapid phase transition (RPT) of CO2 in a high pressure vessel. I looked everywhere, from isochoric data to ...you name it but can't get there... The question: What will the resultant pressure be when solid or liquid CO2 in area A contacts...
  11. L

    How much of visible sky is occupied by CO2?

    My curiosity has been aroused by climate change debates, but my physics is inadequate. Perhaps I can get some help. My question is simply: As viewed from the Earth surface, what percentage of the area of the visible sky is occupied by CO2 molecules? This could be expressed in simple terms...
  12. A

    Will more CO2 increase plant growth?

    I have been thing about this, seems logical in a way, most reactions increase with concentration surface area, temperature and catalysts. Some of the factors are listed here:- http://library.thinkquest.org/12497/factors.htm They seem pretty similar to the one I put in the answers to my...
  13. N

    CO2 solubility in H2O at different temperature and pressure

    Hi all, I'm working on a project of carbon dioxide photocatalytic reduction. I need to dissolved as much CO2 as possible in water. Right now, the idea is to build a pressurized vessile (not overly high, probability no more than 3 atm) operates at room temperature. A diagram of CO2 solubility...
  14. C

    How to calculate heat capacity of supercritical CO2

    Hello, 1. How can I calculate the heat required to raise the temperature of Carbon dioxide. It is at -40C and then it is to be heated to 50 C... The operating Pressure is above critical, so when it crosses the critical temperature point, the liquid CO2 would change into super critical state. (I...
  15. B

    Chemical Thermodynamics: CO2 dissolves in water, find molality and pH.

    Homework Statement When carbon dioxide "dissolves" in water, essentially all of it reacts to form carbonic acid, H2CO3: CO2(s) + H2O(l) <--> H2CO3(aq). The carbonic acid can then dissociate into H+ and bicarbonate ions, H2CO3(aq) <--> H+(aq) + HCO3-(aq). Consider a body of otherwise pure...
  16. H

    Amount of co2 produced for each year

    Does anyone know where i can get a nice table of the amount of CO2 produced for each year with the corrosponding average global temperature?
  17. H

    Understanding Correlation between Temperature & CO2

    What equation do the scientists use to get the correlation between CO2 and Temperature to find the relationship, is it the correlation equation or do they use a different maths equation? and if they don't use the correlation equation could it be used to get the same result?
  18. O

    News Can You Sue a Company for CO2 Emissions?

    This is something I've been wondering about for awhile. People sue companies for damages all the time in cases of pollution. So I was curious if it would be possible for a group of individuals or organizations to sue a company for damages related to CO2 emissions, such as ocean acidification...
  19. J

    Photosynthesis converts CO2 into sugars, can we industrialize this process?

    CO2 appears to create global warming, but is there a way to get rid of the CO2? Could we somehow industrialize the photosynthesis process to get rid of large amounts of CO2? What sorts of issues prevent this solution?
  20. S

    CO2 exchange with Dissolved Oxygen in Water

    I hate to come across as a complete novice, but I am struggling with understanding this. I have found resources for the dissolved oxygen capacity of fresh and salt water based on pressure and temperature. I've also found many resources that infer how this process works, but I am not sure I'm...
  21. S

    Brayton Cycle with Supercritical CO2

    Researchers at Sandia have found the Brayton cycle with supercritical CO2 to be 50% more efficient than existing steam turbine technology used with nuclear reactors: http://www.eurekalert.org/pub_releases/2011-03/dnl-scd030311.php I suppose it's safer too, since the CO2 would help to...
  22. Evo

    Making diesel with sun, water, CO2

    It will be interesting to see if anything comes out of this. Sounds too good to be true. Continued... http://news.yahoo.com/s/ap/20110227/ap_on_bi_ge/us_growing_fuel
  23. F

    How exactly does CO2 behave as a greenhouse gas?

    Hi everyone, This is my very first post here, so hi! I've got a few questions about CO2 that maybe a physics buff can help me out with. I understand the basics about CO2 warming the atmosphere via absorption and re-emission (radiatively or kinetically) of Outgoing Longwave Radiation...but...
  24. K

    Characterize a co2 TEA class 4 laser

    Homework Statement Im working on a lab experiment in my undergraduate physics degree requiring the use of a class 4 laser, i need to characterize this in terms of its power, coherence, pulse duration, wavelength and irradiance. This is a pulsed laser with rough parameters of 1-2J pulse energy...
  25. L

    How does formic acid (under basic conditions) convert to CO2?

    What is the mechanism that results in formic acid quickly converting to CO2. I know this happens under basic conditions so I'm assuming the first step is forming the formate ion.
  26. M

    CO2 gas in a temp-controlled, pressure-controlled container

    The problem: 20 g of dry ice (solid CO2) is placed in a 2.0*10^4 cm^3 container, then all the air is quickly pumped out and the container sealed. The container is warmed to 0 deg C, a temperature at which CO2 is a gas. a) What is the gas pressure? Give your answer in atm. The gas then undergoes...
  27. M

    Compressing CO2 - Can Air Compressor Work?

    Hi, I am doing a design project designing a LCO2 laundering system to operate on the moon. I was looking to get some insight into how you compress CO2. Can a standard air compressor with a storage vessel that can contain sufficient pressure work to compress CO2? Thanks
  28. B

    Why is CO2 liquid less dense than CO2 solid

    I can sort of understand why water is denser than ice, but for CO2 I cannot understand why it is the other way around. Here is my best shot at understanding it: I imagine H2O's solid structure as a hexagon due to the hydrogen bonds, where each point represents one atom. When these bonds are...
  29. U

    How Much Cl2, C, and TiCl4 Are Produced from 1.25 mol TiO2?

    Hi my question is TiO2 + C + 2Cl = TiCl4 + CO2 If you have 1.25 mol TiO2. Answer this question: 1- The mas of Cl2 (1.25 mol TiO2) ((2 mol Cl2)/(1 mol Tio)) = 3 mol Cl2 (3 mol Cl2)((35.453 g Cl2)/(1 mol Cl2)) = 106.359 g Cl2 2- The mas of C (1.25 mol TiO2) ((1 mol C)/(1 mol Tio)) =...
  30. M

    CO2 pressure, consumption, and bubble counters

    In the planted aquarium hobby, CO2 is often infused into the aquarium water using a compressed cylinder of CO2 which runs through a regulator, a needle valve, a bubble counter, and then into the tank. At the end of the gas line, a diffuser is used. The diffuser is porous ceramic material which...
  31. S

    Looking for Henry's Law Constant table for CO2

    As per title. Values from 0 to 20 degrees Celsius are easy to find but I've yet to find one that goes below 0 and up to 80.
  32. I

    Chemical reaction with both O2 and CO2 released as products?

    Is anyone familiar with any chemical reactions that release both oxygen and carbon dioxide gas as products? Or any reactions where oxygen and carbon dioxide are both reactants? Thanks.
  33. L

    Calculating HCO3- in Blood Sample w/ 2.6 X 10^-2 mol/L CO2

    Homework Statement A sample of arterial blood was found to contain 2.6 X 10-2 mol/L dissolved CO2. The pH of the sample was 7.43. If it is assumed that in solution the CO2 forms H2CO3, what is the HCO3- concentration in this blood sample? (pKa for H2CO3 is 6.1) Homework Equations...
  34. R

    CO2 emitters to ward off mosquito's - works?

    Anyone have practical experience with the propane (or vinegar/baking soda) CO2 emitters which purport to reduce mosquito problems? End of biting season for this year, but would like to have an effective approach for next year.
  35. S

    What are the allowed transitions in the pure rotational spectra of CO2 molecule?

    I know that the selection rule is : \DeltaJ = +/- 1 but our prof said that according to some quantum mechanical calculations the odd values of J are not allowed. So, the allowed transitions are : J 0 <-> 1 ; 2 <-> 3 ; 4 <-> 5... as...
  36. Simfish

    Is it really bad for life if the oceans are acidifying under so much CO2?

    Is it really "bad" for life if the oceans are acidifying under so much CO2? CO2 levels were much higher 100 million years ago and I'm sure this implies that ocean acidity was also higher 100 million years ago. And yet, marine life still thrived. Not the same kind of marine life as today, but a...
  37. P

    CO2 Production using baking soda

    So, I'm making a non-yeast based CO2 reactor for my fish tank, and currently the idea has come down to baking soda, an acid, and a iv drip line to control the rate of the reaction. My first question, is what is the best acid to use that will produce stable, non harmful salts as byproducts...
  38. S

    CO2 gas diffusion into a cell factory

    I have to pick the best cell culture vessel: For my experiments, the vessel initially contains 0% CO2. Then it's placed in an incubator set to 37 degreesC and 5% CO2. There is a 1 micron filter i can attach to a port in the vessel that can be 10mm wide or a .2 micron filter can be attached to a...
  39. S

    CO2 gas diffussion and exchange

    I have to pick the best cell culture vessel: For my experiments, the vessel initially contains 0% CO2. Then it's placed in an incubator set to 37 degreesC and 5% CO2. There is a 1 micron filter i can attach to a port in the vessel that can be 10mm wide or a .2 micron filter can be attached to a...
  40. A

    G of CO2 per kWh from burning methane

    http://europe.theoildrum.com/node/6638" has a chart that claims that the burning of methane yields 360 g of CO2 per kWh of energy released. I decided to check that, but I'm not getting the same answer they suggest. Here's what I did: CH4 + 2O2 = 2H2O + CO2 -74.87 + 0= 2*-285.83 + -393.509...
  41. Z

    Why does CO2 keep keep heat within the atmosphere? (on the molecular level)

    I know I know this isn't really related to molecular biology, but I figured since Biologists have a strong background in ecology in most cases, I'd be able to get more help here than the Earth forums (especially because biologists know a lot of chemistry). Basically I understand that CO2 keeps...
  42. S

    Optimizing CO2 Flow in an IR Curing Oven: A Technical Analysis

    Hello all! I'm a sales rep here at << company name removed by moderator>>, we manufacture conformal coating/curing systems. Normally, i'd just ask one of our engineers this question, but production as been shut down for the week as we move to a new facility, so I am out of contact. A...
  43. M

    Find flux of CO2: convert (μmolCO2 (mol air)^-1) to (mgC)(m^-2 of ground hr^–1)

    Homework Statement I am doing an experiment to find the difference in photosynthesis between different areas of grass. I have and am taking more measurements. But essentially I need to convert the data I have into a flux per area over time. the data logger records the data of CO2...
  44. N

    Gas Mixture for a CO2 Laser: Why is the 8:1:1 ratio the most effective?

    Homework Statement I have been doing an experiment using a CO2 laser. One of the procedures is the find the best gas mixture and explain why. I have found the best misture to be 8 parts co2, 1 part n2 and 1 part He, which i have researched and my sources show this is correct. However i also...
  45. E

    The Amount of Human CO2 emissions vs. The Scale of our Atmosphere

    My biology teacher asserted to our class that compared to the vastness of the atmosphere of our earth, the amount of harmful gasses we are emitting is a fraction of a percent and therefore can be dismissed as harmless, and instead we should be worrying about more fragile ecosystems down here on...
  46. D

    Medical CO2 Levels in Small Bedrooms: How Long is Safe?

    Just curious how long an adult person can stay in an average small (W=2.5metre x L=3.5m x H=2.4m) bedroom with the door & window shut before CO2 levels become dangerous? And what about a small room like ~ w1.4m x L1.4m x h1.6m? I assume the small size would make a dramatic difference? Because...
  47. E

    How much does nuclear power reduce CO2?

    This article, http://www.counterpunch.com/stclair03122010.html Sadly for the credibility of the atom lobby, some of their more eye-grabbing numbers don't check out. For example, as noted in a report by the Nuclear Energy Institute, the nuclear industry claims that the world's 447 nuclear...
  48. J

    Measuring CO2 in Natural Gas: Device Needed

    Does anyone know of a device that will measure the percentage of CO2 (about 5% and resolution down to 0.1%) in natural gas, in real time, the gas is at approx 40 bar and 30 Deg C. Thank you
  49. H

    How much CO2 for current US fission plants?

    There is an interesting book out - I believe the title is "COOL IT" - which points that much "green energy " talk is nonsense. For example, the production of concrete necessitates the release of CO2. When you figure in the amount of CO2 generated for the manufacture of the concrete used in...
  50. T

    Degrees of freedom and RMS-speed of CO2?

    Are the RMS-speed of gas particles related to degrees of freedom? I give up! I must consult help no matter how embarrassing it is! Any help is greeted with a big smile! :smile: Does the formula for root mean square speed of particles in a gas (below) apply for all particles...
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