Properties of Carbon Dioxide Vapour

Properties of Carbon Dioxide VapourGreenhouse gases in global warmingThe greenhouse progeny is necessary for Earth to regulate its temperature. Water vapour (H2O), speed of light dioxide ( carbon dioxide) methane (CH4), nitrous dioxide (N2O) and ozone (O3) are some of the gases that contribute to it. These gases are molecules that are made up of more than 2 component atoms. They vibrate upon absorbing thermal infrared radiation and then re-radiate excess energy in all directions. As the Earths surface is now heated by both the emitted radiation and sunlight, temperature increases and thus causing the greenhouse effect.Common Greenhouse swaggeresGreenhouse Effect Greenhouse bobble atmosphericAbsorption Region on Electromagnetic (m)Water vapour (H2O)957600 ppmv0.8 -10Carbon dioxide (carbonic acid gas)3.618401 ppmv2.6, 4, 13Methane (CH4)0.3601780 ppbv3.5 8Nitrous oxide (N2O)0.95320 ppbv5, 8Ozone (O3)0.07228 ppbv0.1-0.3, 9As shown in the table above, water vapour (H2O) contributes the most to the greenhouse effectWhen temperature increases, air humidness increases as well which is positive water vapour feedback. This allows a higher concentration of CO2 in the atmosphere thus further enhancing the warming effect of other greenhouse gases.Carbon dioxide (CO2) contributes kind of a fair amount to the greenhouse effect. Thanks to human activities like deforestation, land use changes and burning of fogy fuel, the atmospheric CO2 concentration has increased by about 120ppm since the Industrial Revolution began, which is more than a third.With an absorption region of 3.5-8 microns on the electromagnetic spectrum, methane (CH4) is elan more active than carbon dioxide as a greenhouse gas. Its greenhouse effect contribution is small due to its low atmospheric concentration. Being in a similar absorption spectrum as H2Oalso masks methanes contribution as work might have been done by H2O already.Nitrous oxide(N2O) is typically organise through production of nitric a cid, combustion of fossil fuel, agriculture sector and burning of . Even though N2O has a low atmospheric concentration, it still contributes a decent amount to the greenhouse effect. This is because it is up to about 300 times stronger as a greenhouse gas than CO2.As ozone (O3) has various concentration at different parts of the atmosphere and has a short lifespan, it is hard to gauge the contribution of the troposphere ozone layer. Ozone generally does not affect much of the greenhouse effect anyway.Lewis Structures of CO and CO2Carbon Monoxidea) Rotational Constant, BTaking largest B = 2.04 and smallest B = 1.51 ,b) Bond Length, bReduced mass of carbon monoxideSince literature value for bring together length, b = 113pm lies within the throw of , and the uncertainty of calculated bond length value is insignifi sternt compared to the calculated value itself, the calculated value can be said to be quite accurate.c) vibrational Wavenumber,Distance of first through in P branch from 2050 cm-1= (5.45 0.05) cmDistance of first through in R branch from 2050 cm-1= (5.72 0.05) cmTaking smallest = 2135 and largest = 2143,d) Force Constant, ke) Molar Zero-Point vibrational Energy, Carbon DioxideRotational Constant, Taking smallest = 0.302 cm-1 and largest = 0.46 cm-1,Since literature value for = 0.390 lies within the range of , and the uncertainty of calculated bond length value is insignificant compared to the calculated value itself, the calculated value can be said to be quite accurate.Vibrational ModesCO2 is a linear molecule with 3 atoms. Therefore, it has 3 translational modes, 2 rotational modes, and 3N-5 = 4 vibration modes 1 symmetric stretch, 1 asymmetric stretch and 2 bending modes. The mode at 667 cm-1 is said to be twofold degenerate because the 2 bending motions are essentially the same, rightful(prenominal) deforming in different coordinate directions.Exclusion Rule no modes can be both infrared and Raman active for a molecule with a nerve cent re of symmetry. CO2 has a centre of symmetry therefore relevant to the rule.For infrared spectroscopy, the 2 bending and the asymmetric stretching modes can be observed. This is because these modes induce a dipole change in their motions. For Raman spectroscopy, symmetric bending can be seen. This is because when the O atoms move away from the centre C atom in an play off distance, the electron density cloud changes with the change in size of molecule, thus causing a change in polarizability.Bond Length, b Force Constant, kSince literature value for lies within the range of (119.612.5)pm, and the uncertainty of calculated bond length value is insignificant compared to the calculated value itself, the calculated value can be said to be quite accurate.For symmetric stretch, k CO2 2. Heat CapacityMolar constant-volume heat capacityFor CO2 Translational modes, , Vibrational modes, ,Rotational mode, Total internal energy, At very high temperatures, the theoretical maximum internal energy = as all modes are activated at that point.Max. constant-volume heat capacity,However, at low temperatures not all rotational and vibrational modes are active.Contributions of different modes at low temperaturesRotational ModesRotational temperature, Vibrational ModesVibrational temperature, Symmetric stretch () Bending modes () Asymmetric stretch () Graph of against TConvert molar constant-volume heat capacity to molar constant-pressure heat capacity with standard Gas Law , (R = ideal gas constant)The graph for observational and calculated info is the same until around T=1600K where the 2 lines diverge with the experimental data to be higher than calculated data. This shows that the Ideal Gas Law only applies to relatively low temperatures. Kinetic Theory of Gases and LiquidsMean free path of CO2Mean free path average distance travelled by molecules between collisions mark of collision , Collision cross-section (area covered by a molecule and within which the pres ence if the centre of another molecule counts as a collision)Collisions happen at 90o angles on average, mean speed = 8.Viscosity of CO2 vapourNewtons Law of Viscosity Newtons 2nd Law Force = rate of change of momentumFrom plane at 0 from plane mean fall down velocity = mean momentum of Roughly1/6th of the molecules move in the +z direction.Number of molecules entering 0 from per unit time = rate of momentum = Rate of momentum entering 0 from = . By calculating the difference between the two rates, net rate of the momentum transported across the plane at 0, and by using , the viscosity, can be estimated. 8 (mean velocity), (path length)Viscosity is predicted to be proportional to the square root of temperature and independent of density.Liquefaction in a condenser9Modify the Ideal Gas Law to obtain Van der Waals Equation of State.References1 https//climate.nasa.gov/causes/ (accessed 14th March 20172 Greenhouse Gas Absorption Spectrum (n.d.) available fromhttp//www.meteo r.iastate.edu/gccourse/forcing/spectrum.html (accessed 14th March 2017)3 Barrett Bellamy Climate Greenhouse Gas Concentrations (n.d.) available from http//www.barrettbellamyclimate.com/page22.htm (accessed 15th March 2017)4 Monte Hieb (2015) Water Vapor Rules the Greenhouse System. Available from http//www.geocraft.com/WVFossils/greenhouse_data.html5 Project Learn at http//www.ucar.edu/learn at the University Corporation for Atmospheric Research (UCAR) https//www.ucar.edu/learn/1_3_1.htm (accessed 15/3/2017)6 Barrett Bellamy Climate Greenhouse Gas Spectra (n.d.) available from http//www.barrettbellamyclimate.com/page15.htm (accessed 15/3/2017)7 NIST Standard Reference Database 101 (September 2015) Listing of experimental data for CO2 (Carbon dioxide) Available from http//cccbdb.nist.gov/exp2.asp?casno=124389 Accessed 10 Mar 20168 Dr Joao Cabral (n.d.) Properties of Matter Lecture Notes. Department of Chemical Engineering, Imperial College London9 Steve 2010 The Freezing Point and Th e Dew Point sectionalisation 2 available from https//stevengoddard.wordpress.com/2010/09/05/the-freezing-point-and-the-dew%C2%A0point-part-2/