1 / 8

Water and Gases

Water and Gases. Pure water (evaporation generally purifies water) interacts with gases in air: Equilibrium between air and gases: H 2 O + CO 2  H 2 CO 3(aq) How do we determine conc. H 2 CO 3(aq) ??. Henry’s Law. A description of gas solubility of gases in solution

breena
Download Presentation

Water and Gases

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. Water and Gases • Pure water (evaporation generally purifies water) interacts with gases in air: • Equilibrium between air and gases: H2O + CO2 H2CO3(aq) How do we determine conc. H2CO3(aq)??

  2. Henry’s Law • A description of gas solubility of gases in solution gas(g)↔ gas(aq) O2(g)↔ O2(aq)

  3. What is the difference in O2 at equilibrium with 5ºC water vs. 35ºC water?? • Compare that with SO2…

  4. Gas production? • What processes produce gases? • Degassing from melts • Formation and degassing from metamorphic reactions and hydrothermal systems • Diagenetic reactions, petroleum genesis • Biological production

  5. Oxygenic Photosynthesis Chlorphyll a (P680) is very oxidized (E0=+1.1V), enough to oxidize H2O. BUT e- excitation takes it to E0=-0.7V, not enough to reduce NADP+ to NADPH. Thus a need for 2 photosystems…. Water-oxidizing complex is key – Mn4Ca-complex that oxidizes H2O to O2 in 4 steps (S0 through S4)

  6. Diffusion, Fickian Diffusion from high to low levels.. Where D is the diffusion coefficient, dc/dx is the gradient, and J is the flux of material

  7. Groundwater • Precipitation that does not run-off into rivers percolates into soils, sediments, and into basement rock fractures to become groundwater • Water always flows down-hill • Darcy’s Law describes the rate of flow where,Q = volumetric flow rate (m3/s or ft3/s),A = flow area perpendicular to L (m2 or ft2),K = hydraulic conductivity (m/s or ft/s),l = flow path length (m or ft),H= hydraulic head (m or ft), andd= denotes the change in h over the path L.

  8. Groundwater Chemistry • Just like other waters, encounters minerals, gases, etc. • Some key differences from other waters: • PCO2 variable – respiration! • Segregation of flowpaths in different units

More Related