Co2 Definition and 309 Threads

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. C

    Planet with dense neon atmosphere and streams of CO2

    Idea is a cold planet with dense atmosphere (10 atm) where human can survive, while a liquid carbon dioxide would be possible. As the main component of atmosphere I think about neon, because it should not cause nitrogen narcosis: http://en.wikipedia.org/wiki/Nitrogen_narcosis#Causes...
  2. R

    How water, CO2, sand etc extinguish fire?

    Well all answer this basic question by saying that water decreases the heat energy of fire, CO2 blocks O2 from reaching fire.But what about coke, higher molecular gases.
  3. Ivan Seeking

    Can CO2 Levels in Cars Cause Drowsiness While Driving?

    After almost falling asleep while driving the other day, I got to thinking about CO2. I started to wonder if due to normal respiration of the driver and or occupants, CO2 levels in a car can rise to levels that can inhibit responses or even lead to unintended sleep, and make driving unsafe. I...
  4. Spinnor

    Animation Shows One Year of CO2 Swirling Through the Atmosphere

    From NASA, a year in the life of Earth's CO2, at, http://www.wired.com/2014/11/nature-run-co2-visualization/
  5. F

    How does CO2 convert infrared radiation to heat

    I'm trying to understand the issue of CO2 and global warming better. Can anyone explain to me the mechanism by which CO2 in particular converts infrared radiation to heat. I've had a semester of college chem and three semesters of physics, but I'm not sure what theory I should be able to use...
  6. W

    Does Atmospheric Pressure or Temperature Determine the State of CO2?

    Let's say you have a 20 bar atmosphere of 95% nitrogen, 3% oxygen, 1% argon and 1% Co2 cooled to 0 F. Would Co2 be liquid or gas?
  7. A

    How Do You Convert CO2 PPMV in Air to PPMW in Water?

    Measuring CO2 I have been searching for an answer to this for quite a while, so I'm hoping somebody here can help me out. I've spent quite a bit of time digging and reading, and I've found plenty of information, but I'm not always sure what to make of it. I am working on making myself a small...
  8. J

    What function best fits the CO2 doubling curve?

    The IPCC uses a figure 1.2°C for the direct response to a doubling of CO2, from 280 ppm to 560 ppm. http://www.grida.no/climate/ipcc_tar/wg1/pdf/tar-01.pdf I came up with an equation of 4(log 560)-4(log 280)= 1.2041199. Is this the best way to fit this curve?
  9. O

    Produce Methane Via CO2 + H2O ?

    it is known that the standard combustion enthalpy of methane is -882 kJ/mol CH4 + 2 O2 --> CO2 + 2 H2O Hc = -882 kJ based on hess's law, if a reaction is reversed, so does with the enthalpy CO2 + 2 H2O --> CH4 + 2 O2 Hc = +882 kJ which makes the reversed reaction become...
  10. B

    Measuring CO2 Useage on Moving Objects

    I have a project that I have been thinking about and need to us CO2 for it. What ways are there to measure the amount of CO2 left in a cylinder if its mounted to a moving object? I thought about the normal scale method but with bumps it wouldn't be accurate. You can't really measure pressure...
  11. Y

    Calcium Carbonate & Dicalcium Phosphate - CO2 Problem

    Hello everyone, I would really appreciate your help on figuring out the issue of undesirable CO2 production in this situation. Homework Statement In a mixture of CaCO3 + CaHPO4; I am observing undesirable CO2 production under conditions of 20-25°C (room temp) and an undesirable excess of...
  12. Q

    Electrophilic nature of Carbon in CO2

    How is the carbon in carbon dioxide electrophilic? There is no partial positive charge on the carbon in carbon dioxide because the molecule is symmetrical.
  13. N

    H20, CO2 and O2 in a Closed Container for a Long Time

    How much oxygen would make it's way down to the water if no mixing happens when put into container? I always hear of blanket of CO2 over a liquid. I'm trying to relearn some thermodynamics principles. Would the partial pressure between the CO2 never allow the oxygen diffuse into the water if...
  14. N

    Calculate CO2 Dissolved in 5M KOH Solution | Pressure & Temp

    Can someone tell me how much CO2 I could dissolve in a 5M aqueous solution of potassium hydroxide and how to calculate this? This would be done at high pressure and low temperature, and if you can tell me what temperature and pressure would be optimal and why, or how to figure that out...
  15. S

    Calculating the pH of CO2 dissolved in 1l of water

    OK folks, first of all, let me thank those of you who have helped me with previous questions... perhaps this is why I keep coming back! This time, I'm just asking those of you who are better than I am at this if I did this right and thus, got the correct result. I think I did, but since...
  16. D

    What is the Correct Method for Measuring CO2 Gas Volume?

    Hi! I am trying to evaluate the amount of CO2 gas produced from the reaction of CaCO3 and HCl. Theoretically the amount of gas that can be achieved from the 0.1 g of calcite is around 24 cc (T=21 degree and P is 1010 mb). But, the experimental value that I obtained is around 30 cc. I have no...
  17. N

    Disadvantages of CO2 Scrubbers?

    Hello, I'm not sure if this is in the right section, but I figured chemical engineering would be best for this. I wanted to know what kind of disadvantages there are for today's CO2 scrubbers and how they can be improved. I am wondering this because I am doing a clean tech competition and...
  18. anorlunda

    Antarctic Temp Reaches -99.2C: Could CO2 Snow Have Fallen?

    News reports in the past day tell us tha the temperature in Antartica reached -99.2C (-135.8F). Wikipedia says that the melting point of CO2 is -78C (-109F) Does that imply that there might have been natural CO2 snow falling there? If so, that is a very interesting fact.
  19. C

    Methane and CO2 atmospheric lifetime math problem

    Homework Statement On a per-molecule basis, methane is 26 times more effective as an infrared absorber than is CO2. Calculate the corresponding ratio on a per-unit-mass basis, and compare it with the 20-year GWP for methane. What's the reason for any discrepncy you find? (CO2 atmospheric...
  20. F

    Is This Carbon Monoxide Calculation Correct?

    Homework Statement calculate the amount of carbon monoxide necessary to form 100 g of carbon dioxide. The Attempt at a Solution 2CO + O2 -> 2CO2 Oxygen atom mass ≈ 16μ Carbon atom mass ≈ 12μ There are 2 carbom atoms and 1 oxygen atom 100/16+24 = 2.5 2.5(16+12) = 70g Answer: You need 70g...
  21. B

    Calculating Bore and Stroke for a CO2 or Air Powered Engine

    To give a little background I have machine tool training but not much other than what I have taught myself in general physics. Its a VERY interesting subject for me and I have thought about going back to college just to take a course or two relating to it. I come up with various ideas I would...
  22. C

    Developing Tiny CO2 Cartridge - Questions & Answers

    Hi folks, I was interested in developing a tiny CO2 cartridge and wanted to ask a few questions of anyone who could/would answer. The cartridge should be as small as possible and preferably as flat as practicable, but it could simply be cylindrical. It should contain enough CO2 to fill around...
  23. K

    Rotation of CO2 bonds and triple bonds.

    I read in several websites that triple bonds cannot rotate freely. However, I've also read in the book "Chemical Principles" the following lines: "Various types of evidence suggest that the electron density around the two C-O bonds in CO2 is actually cylindrically symmetric—that is, the...
  24. W

    Liquid CO2 rivers, lakes or oceans

    Lets say you have planet with 2 Earth radii and 8 Earth masses. The atmosphere is 50 bar and is made up of 85% nitrogen, 10% hydrogen 3% argon, 1% CO2 and 1% other gases. The planets average temperature is 280 K/44 F. Since CO2 is a liquid at this pressure and temperature would it form rivers...
  25. P

    How to find the concentration of CO2 in 1M NAOH solution?

    I done the absorption experiment i.e absorption of CO2 from air using 1M NaOH .Can anyone please tell how to analyse the Liquid sample after absorption. I found the concentration of NaOH after and before the experiment,difference in Concentration gives the concentration of CO2.is it the...
  26. F

    Atmospheric Stoichiochemistry: what mass of CO2 is produced?

    I have two problems actually: Problem 1 Homework Statement What mass of carbon dioxide can be produced at a temperature of 1500 *C and an atmospheric pressure of 92.5 kPa, if 15.5 L of acetylene gas is burned at STP? Homework Equations PV = nRT P1V1/T1 = P2V2/T2The Attempt at a Solution...
  27. Esnas

    CO2 Concentration Tops 400ppm for the First Time in Human History

    This was described by Michael E. Mann,professor of meteorology at Penn State University. http://www.meteo.psu.edu/holocene/public_html/Mann/news/interviews.php Others have had readings that give similar results. "While scientists and environmentalists have used the daily milestone to...
  28. C

    How can I perform electrolysis on CO2?

    I want a way to perform electrolysis on CO2, in order to split it into carbon and oxygen atoms. Does anyone have any ideas on how I could do this?
  29. R

    Reactants of CO2: NaOH & H2CO3 |Chemical Reactions

    I want to ask that which element can react with CO2 gas to split c and o or what will happen if NaOH reacts with h2co3 NaOH+H2CO3---> 2CH3COONa+2H2O+5O2 IS IT CORRECT?
  30. D

    Amount of CO2 vaporized in a phase change from liquid to solid & vapor

    Homework Statement Saturated liquid CO2 is at T= 293 K and P=5.72*10^6 Pa and undergoes throttling to P=1.01*10^5. The resulting solid and vapor mixture is at T = 195 K. What fraction of the carbon dioxide is vaporized? (The enthalpy of the saturated liquid in the initial state is 24,200...
  31. supak111

    12g CO2 cartridge energy in J?

    I would love to know much total energy, in Joules is in a typical paintball/airsoft 12g CO2 cartridge? Thanks everyone.
  32. S

    Outgassing of CO2 from a lake after lowering the water level

    Hi folks! English is not my native language so please excuse my bad grammar. I am a geology student working on a project about a lake when an interesting puzzle piece - a newspaper article from 1844 - came up. This is not homework and I don't even know if a solution exists to my question at...
  33. T

    How to Resolve H2O and CO2 Pressure Imbalance in Open Line Mixing?

    H2O and CO2 must mix in an open line (not closed pressurized vessel) via stainless steel membrane; the dilemma is: H2O incoming line pressure is approximately 50psi and CO2 line pressure is approximately 100psi. The problem arises when both elements collide at the point of the membrane where...
  34. M

    Can Sodium Hydroxide Effectively Capture and Release CO2 from the Atmosphere?

    I was thinking how it is possible to obtain carbon dioxide capturing it from the atmosphere and releasing it from the solution. I've read that "air meets a mist of a sodium hydroxide solution...the carbon dioxide is absorbed by reaction to form sodium carbonate...this solution is pumped into an...
  35. R

    How Long Does It Take for CO2 to Diffuse in a Nitrogen-Filled Vessel?

    Ok so I wish to try solve a problem at work I will try explain as best I can . Problem Definition; Filling of a bundle of cylinders 17 x 50litre ( 850 000 k/m^3). 30 % Co2 in the cyindrical vessal followed by input of Nitrogen 70% to a final pressure of 200 bar Due to production...
  36. L

    Test question: Respiring cells release CO2 into the bloodstream

    Test question: "Respiring cells release CO2 into the bloodstream..." 1. 2. For this question, I was thinking about the nature of CO2. It's not an acid or base, so how could it drop or raise the pH level?! So I put that the pH level won't change (B), but the real answer is C (it will...
  37. N

    IR Spectra: Why is CO2 a doublet at 2350cm-1?

    CO2 is supposed to create a "doublet" peak at 2350 cm-1 according to my IR correlation chart. Why is this doublet created? As DrDu explained in my previous post, two peaks are seen for the N-O bond because it has IR-active symmetric and asymmetric stretches. But CO2 is a linear molecule, and...
  38. E

    Automotive Why Diesel Engines Produce Less CO2: A Thermodynamic Approach

    As the title says, why diesel engines produce less CO2 than gasoline engines and how is this related to the more torque and less power in diesel engines? PLEASE only a fluid dynamics or thermodynamics approach. Spent hours on searching to find why petrol engines produce more CO2 emissions...
  39. A

    Questions about calcium hydroxide as co2 absorber.

    I want to improve our company's packaging strategy for live seafood products. The catch is, the box has to be sealed completely. This causes problem with the ever increasing level of CO2 and not enough o2. Now, since the box is tightly packed with the products and other materials for cushion...
  40. D

    CO2 reaction with water and bicarbonates?

    Hi everyone! I'll say it from the start that I'm not knowledgeable with chemistry but I'll call for anyone's help in making me understand this simple reaction. I'm interested in finding out what reactions are occurring when CO2 is dissolved in water. The scope is for my hobby which is...
  41. A

    Building a CO2 Thermosyphon: Tips for Compressing Gas to 7MPa Pressure

    Is there a way to build a rig so that I could compress CO2 gas to apressure of roughly 7MPa? I am building a CO2 Thermosyphone and need high pressure CO2 in order to get convection to occur. Any help or advice would be greatly appreciated
  42. C

    Which Solutions Will Liberate CO2 from Trioxocarbonate Salt?

    Homework Statement I have two questions: (1) Suppose we have solution W, X, Y and Z. Their pH are 8, 12, 4 and 2 respectively, from the information given which of the solution W, X, Y and Z will liberate carbon (IV) oxide from trioxocarbonate (IV) salt? (2) Between CaCO3 and CaO, which is...
  43. D

    Calculating coal CO2 emission intensity (kg CO2 emitted/kWh delivered)

    Hi all, Would really appreciate some help on this problem I can't seem to figure out. Brown coal has an energy content of 15MJ/kg, carbon content 65% by weight, burning in a 30% efficient steam power plant. Calculate the CO2 emission intensity (kg CO2 emitted/kWh delivered).Assume complete...
  44. U

    Automotive Some ideas for a CO2 emission reduction device to be attached to cars

    Hi, I and my team-mate have proposed an idea to develop a CO2 emission reduction device to be installed in automobiles. We have mentioned that it will operate on the principle of 'active adsorption of CO2 on charcoal'. However, although the basic scientific principle is pretty simple...
  45. S

    Calculating CO2 Needed to Reduce pH of NaOH Solution to 12

    I am trying to perform the calculation that will tell me how much (mass or moles) carbon dioxide (CO2) I would theoretically need to bubble through a 3 liter solution of a 2.6 M aqueous sodium hydroxide (NaOH) solution in order to reduce the pH of the solution to 12. I know that the reaction...
  46. A

    What Temperature is Required to Break CO2 Molecules?

    I was wondering at what heat does CO2 begin to breakup as a molecule? If I make an electrical arc and put it through air will I be breaking up CO2?
  47. berkeman

    Small Liquid CO2 Manufacturing Machine?

    At my work, we go through a lot of liquid CO2 (LCO2), and dealing with the 500 pound LCO2 dewars is a real pain. I'd like to look at options for us making our own LCO2 instead, but have been having trouble finding information about small-scale LCO2 generation on the web. We use the LCO2 for...
  48. M

    Ionize N2 & CO2 at 50g/s - Easiest Way?

    hi everyone, is it possible to easily ionize N2 and CO2 at a high flow about 50g/s, and which is the easiest way? thanks
  49. T

    Medical Does CO2 and HCO3- inhibit N2O absorbtion into the blood?

    I'm asking because I want to know whether the technique of rebreathing N2O back into a balloon reduces the the amount absorbed when inhaled again. It obviously dilutes the N2O with some CO2 and water vapor, but I assume the dilution is pretty minimal.
  50. N

    Information on photo-dissociation and co2

    Hi, I have been reading up on photo-dissociation of CO2 and I all I can find is wiki and a couple other sources. I was wondering if anyone knew of any good sources of information on photo-dissociation of co2. Like on what wavelengths of EM are best and the energy needed to cause the breaking of...
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