prelim_2_key

prelim_2_key - Chemistry 288 Last COVER Prelim II I<-e (...

Info iconThis preview shows pages 1–4. Sign up to view the full content.

View Full Document Right Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: Chemistry 288 Last COVER Prelim II I<-e ( ? First Tuesday, April 18, 2006 7:30 - 9:00 PM, Baker 219 Middle Initial Complete academic integrity is expected of all students of Cornell University at all times, whether in the presence or absence of members of the faculty or teaching staff. Understanding this, I declare that J shall not give, use, or receive unauthorized aid in this examination. Your Signature: _ As soon as you are told to begin, check to see that your examination booklet is complete, and notify a proctor immediately if it is not. Your examination booklet should contain 9 numbered pages including one work sheet. You may leave when finished, but please do so quietly. Question Al (14) Question Cl (10) A2 (18) C2 (20) (32) C3 (13) C4 (10) (53) Question 81 (3) 82 (4) B3 (4) B4 (13) Question D1 (10) (24) D2 (24) D3 (13) (47) Extra Credit (9) I. 2. ___(6) ___(3) TOTAL 156 + 9 A. NONIDEAL SO LU TIONS At certain temperature pure liquid A has a vapour pressure of 100 mm Hg. It forms a non-ideal solution with substance B (which it does not "liken). It also forms a non-ideal solution with substance C (which it does "like"). In each case when X A < 0.20 component A exhibits Henry 's law behavior (P A = k A X A ) . In one mixt ure (you j udge which) k A = 50 mm Hg, in the other it is 150 nun Hg. a) In the following two graphs draw the Henry 's Law extrapo lation and the Raoult' s <0 Law extrapolation to pure A (use dashed lines). ~-, Ale mixt ure AlB mixture I 150 P A I 150 P A 15 15 I ~ I ~ 100 m 10 10 0 m m ~ m J------ . v 50 Hg 5 I r 50 Hg v ~ 2 '> ~ I , o {),la . t '() 1- X A o r-. 0.30 X A 1.00 0.30 1.00 Now go to mole. fraction X A = 0.30 in the mixture with C. QJ b) Next draw (in solid) a likely actual vapor pressure curve for each of the two mixtures. = O Q3 2- a) What is the value Of PAaccording to your curve?- 2 ~ ""...-' 11'\ Determine the activity and the activity coefficient of A at this mole fraction (X A = 0.30) o f A in C. l ( i) for Raoult's Law (R· L) based standard stale "I ii) for Henry's Law (H-L) based standard slate o- -,o ,/y rz 7c- I 0-, :;. . R ,., I" 1./ If :;: I' ) 2 Answers aA YA Raoul t's Law { , £ s () ,l5 .5 Henry's Law r: , 5 0 1./_ 7 , The standard chemical potential of A in this mixture (d ~does not depe nd) on the choice of the standard state.-~- The chemical potentia l of C in this mi xture (dep ends, jtloes not depe ~ on the choice of standard state. ~ B, COLLIGATIVE PROPERTIES...
View Full Document

This note was uploaded on 09/28/2008 for the course CHEM 2880 taught by Professor Freed, j during the Spring '06 term at Cornell.

Page1 / 11

prelim_2_key - Chemistry 288 Last COVER Prelim II I<-e (...

This preview shows document pages 1 - 4. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online