1 / 17

Microscopic view about Raoult law and Henry Law

p. k x,B. k x,A. Solute molecule. Solvent molecule. A. B. x B. x B →0. x B →1. Microscopic view about Raoult law and Henry Law. Gas A,B y A ,y B. Liquid A, B x A ,X B. Ideal solution. The solvent and solute both follow Raoult Law. Binary system. Scuba diving.

Download Presentation

Microscopic view about Raoult law and Henry Law

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. p kx,B kx,A Solute molecule Solvent molecule A B xB xB→0 xB→1 Microscopic view about Raoult law and Henry Law

  2. Gas A,B yA,yB Liquid A, B xA,XB Ideal solution The solvent and solute both follow Raoult Law Binary system

  3. Scuba diving Vaporizable solutes follow Henry Law 25℃, sea level, O2 in air PO2=21kPa

  4. kA P xA Chemical potential of B, X=1, follow Henry Law Ideal diluted solution Solvent follow Raoult’s law Solute follow Henry’s law

  5. Chemical potential of reference/standard state: Solute in diluted solution

  6. solute solvent 4.5 Colligative properties of diluted solution The solute is not volatile The decrease of vaporizing pressure Freezing-point depression The elevation of boiling point Osmosis: osmotic pressure

  7. Freezing-point depression (l)  (s) Tf* (sln)  (s) Tf 1(sln) = 1*(s) 1y(l) + RT ln x1 = 1y(s) RT ln x1 = –[1y(l) – 1y(s) ]

  8. X2 is small lnx1=ln(1– x2)  x2  Tf should be small, too freezing point lowering coefficients Note: diluted solution, separate pure solid (solvent)

  9. Boiling-point elevation (boiling point elevation coefficients),Unit:

  10. Semipermeable membrane Osmosis pressure Osmosis phenomenon and osmosis pressure A(sln)=Ay(l) + RT ln xA<A*(l) P↑, μ ↑

  11. Osmosis pressure: meaning, measurement and application Van’t Hoff equation Δp=0.053Pa;ΔTf=0.002K; π=2400Pa 20℃,mB=0.001mol.kg-1

  12. Colligative properties of diluted solution: Application examples • Mr. Tian Wen-fei • Mr. Tian Wen-zhi

  13. γcs2 γacetone 4.6 Real solution: activity of solute and solvent By R.L. Judged by Raoult law Or by Henry Law

  14. Determination of activity of solvent (1) p1 = p1* a1

  15. Example 1: Activity of water in aqueous solution P0, Aqueous solution Tf=– 15℃ Question: a(water)=? Osmosis pressure of the solution. Answer: a1=0.857

  16. 40000Pa P PB PA 1 0 xA Example 2: Acetic acid(A)/benzene(B) solution By R.L: By R.L By H.L mixG=RT(xA ln aA + xB ln aB)= – 1167J

  17. Homeworks • Y:P101:15; P104:17,18 P106: 22 • P110:23 • A: P190: Exe7.19(b); Problem7.1 • P192: application7.23 Term seminar report : May 21: May 23: May 30: June 04: June 06: 10 min/person

More Related