1 / 18

Buffers

Buffers. Activity. ΔG mix = x A . (μ o A + RT . ln a A ) + x B . (μ o B + RT . ln a B ). μ o B. x A . μ o A + x B . μ o B. ∆ a G. RT . ln a B. μ B = μ o B + RT . ln a B. x A . RT . ln a A + x B . RT . ln a B. μ o A. ΔG mix = x A . μ A + x B . μ B. RT . ln a A.

brunnerj
Download Presentation

Buffers

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. Buffers

  2. Activity ΔGmix = xA.(μoA + RT.ln aA) + xB.(μoB + RT.ln aB) μoB xA.μoA + xB.μoB ∆aG RT.ln aB μB = μoB + RT.ln aB xA.RT.ln aA + xB.RT.ln aB μoA ΔGmix = xA.μA + xB.μB RT.ln aA μoA + RT.ln aA = μA xB xA A B composition

  3. Buffer µ0CO2 CO2 RT·ln(aCO2) ∆fG µCO2 µ0H2O H2O RT·ln(aH2O) xCO2 µH2O CO2 H2O Bulk composition

  4. Buffer µ0CO2 CO2 RT·ln(aCO2) ∆fG µCO2 µ0H2O H2O CO2- buffer RT·ln(aH2O) µH2O CO2 H2O Bulk composition

  5. Buffer µ0CO2 CO2 RT·ln(aCO2) ∆fG µ0H2O H2O RT·ln(aH2O) CO2- buffer µCO2 µH2O xCO2 CO2 H2O Bulk composition

  6. Defining a O2-buffer 6 hematite = 4 magnetite + O2 6 Fe2O3 = 4 Fe3O4 + O2 O2 = 6 Fe2O3 - 4 Fe3O4

  7. Defining a O2-buffer 6 hematite = 4 magnetite + O2 6 Fe2O3 = 4 Fe3O4 + O2 O2 = 6 Fe2O3 - 4 Fe3O4 Define new phase: “OHM” Composition: O(2) ∆aGOHM = 6·∆aGhem - 4·∆aGmt

  8. Defining a O2-buffer 6 hematite = 4 magnetite + O2 6 Fe2O3 = 4 Fe3O4 + O2 O2 = 6 Fe2O3 - 4 Fe3O4 Define new phase: “OHM” Composition: O(2) ∆aGOHM = 6·∆aGhem - 4·∆aGmt OHM-BUFFER O(2) OHM *OHM ST 0.000 000000.000 000.000000 0.000000 CP1 0.000000 0.00000 0.00 0.0 COM HEMATITE[6]MAGNETITE[-4] 0 HEMATITE

  9. Defining a O2-buffer 6 hematite = 4 magnetite + O2 6 Fe2O3 = 4 Fe3O4 + O2 O2 = 6 Fe2O3 - 4 Fe3O4 Define new phase: “OHM” Composition: O(2) ∆aGOHM = 6·∆aGhem - 4·∆aGmt code for special phase: *OHM (In input: use = .. ,OHM) composition abbreviation name OHM-BUFFER O(2) OHM *OHM ST 0.000 000000.000 000.000000 0.000000 CP1 0.000000 0.00000 0.00 0.0 COM HEMATITE[6]MAGNETITE[-4] 0 HEMATITE all = 0 phase to discard ∆aGOHM = 6·∆aGhem - 4·∆aGmt Combination of other phases Activity(not used)

  10. Defining a O2-buffer 6 hematite = 4 magnetite + O2 6 Fe2O3 = 4 Fe3O4 + O2 O2 = 6 Fe2O3 - 4 Fe3O4 Define new phase: “OHM” Composition: O(2) ∆aGOHM = 6·∆aGhem - 4·∆aGmt code for special phase: *OHM (In input: use = .. ,OHM) composition abbreviation name OHM-BUFFER O(2) OHM *OHM ST 0.000 000000.000 000.000000 0.000000 CP1 0.000000 0.00000 0.00 0.0 COM HEMATITE[6]MAGNETITE[-4] 0 HEMATITE all = 0 phase to discard ∆aGOHM = 6·∆aGhem - 4·∆aGmt Combination of other phases Activity(not used) -OHM-BUFFER O(-2) -OHM *OHM ST 0.000 000000.000 000.000000 0.000000 CP1 0.000000 0.00000 0.00 0.0 COM OHM-BUFFER[-1] Negative buffer (no comment) If confusion is the first step to knowledge, I must be a genius. (Larry Leissner)

  11. Defining a O2-buffer domino 600 4000 1 FE(1)O(1) *,OHM Input:

  12. Defining a O2-buffer domino If hematite is not discarded .... Non-unique Equilibrium: Indifferent State OHM-Buffer ΔfG magnetite hematite FeO O2

  13. Defining a O2-buffer domino 600 4000 0 SI(50.36)AL(30.54)FE(6.23)MG(2.46)CA(1.07)NA(4.62)K(4.73)O(160.965)H(60)O(30)O(20) * TN205 fin Input:

  14. Defining a O2-buffer domino 600 4000 0 SI(50.36)AL(30.54)FE(6.23)MG(2.46)CA(1.07)NA(4.62)K(4.73)O(160.965)H(60)O(30)O(20) *,OHM TN205 fin Input:

  15. Defining a O2-buffer domino SI(50.36)AL(30.54)FE(6.23)MG(2.46)CA(1.07)NA(4.62)K(4.73)O(160.965)H(60)O(30)O(20) with hematite-magnetite buffer TN205

  16. Defining a O2-buffer 3 hematite + H2 = 2 magnetite + H2O 3 Fe2O3 + H2 = 2 Fe3O4 + H2O H2 = 2 Fe3O4 + H2O - 3 Fe2O3 Define new phase: “HHM” Composition: H(2) ∆aGHHM = 2·∆aGMt + ·∆aGH2O - 3·∆aGhem code for special phase: *OHM (In input: use = .. ,OHM) composition abbreviation name HHM-BUFFER H(2) HHM *HHM ST 0.000 000000.000 000.000000 0.000000 CP1 0.000000 0.00000 0.00 0.0 COM MAGNETITE[2] STEAM[1] HEMATITE[-3] 0 HEMATITE -HHM-BUFFER H(-2) -HHM *HHM ST 0.000 000000.000 000.000000 0.000000 CP1 0.000000 0.00000 0.00 0.0 COM HHM-BUFFER[-1] all = 0 phase to discard ∆aGOHM = 6·∆aGhem - 4·∆aGmt Combination of other phases Activity(not used) Negative buffer (no comment)

More Related