key_exam_3_F06

key_exam_3_F06 - GRADE I = % 1) a)(IOpts) One mole of...

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Unformatted text preview: GRADE I = % 1) a)(IOpts) One mole of benzene is mixed with two moles of toluene at 60C. The sanitation vapor pressure of benzene is 51.3kPa and toluene is 18.5kPa. Assuming an ideal solution, at what is the pressure of this mixture. At what external pressure will this mixture just begin to boil? What will the composition of the vapor he at this pressure? ‘ .- _ . Xe3§§:&% X1“:z:@ s5??? i ? égfifi. ,.n...,«r’-~:_.."will? ‘1 P Si; ' "5} 2' fl g ,5 gigs? r y?“ as» g eggs“) Av , as? {e s“) M i b) (Spts}Assuming the mixture is ideal at all concentrations, draw a graph of Pressure vs. beenzene). Plot two lines - the total pressure and the rough composition of the vapor. Include i” “anigmww .s. .0.“ for both liquids. This graph was not in the set of homework. ..bui1d it now. i -, J a' sense gees Pail-flags I “ 54-? E...- Q E 2) (15 pts) Draw a tiii‘ggéémponent liquid system— temperature vs mole fiaction—— phase diagram. The system is immiscible at the lowest temperahrre on the diagram beginning at 0.1XA and ending at 0.9XA. Both liquids are miscible above 50K. The boiling point of A is 100K, B 150 K and form a maximmn boiling azeotrope at 200K at XA= 0.25. Marked points — need not be to perfect scale. DO # 3 or 4 Cross off the one you do not what graded ~ if not indicated we will. grade #4 only 3) We know that = ~§ (note: S per mole). P 5623;? 25? g;ng an. >7 i s! a) (5 pts) Which is a larger change per degree— the change in a for a liquid or a gas? Why. C . O ) alga/V - w a a «I M ‘3 xxx-W _ g i 1 .r /M .mnM'WMm.Wfl4“W'—' 1‘: “filemical potential above explain why gas soiubility in a liquid decreases as (,— temperature increases. (Think a out a carbonated soda, or gases dissolved in blood-- start at i ethbn and Increase the temperature 1 degree) fingg 525 fiagflw i 1 gm” (mmmvregm‘ Wig; "Wail! 5 a? HQ. “falsified twawmm M93; ngfifif‘iweb “A “g2? mam? . . . . tat» 624% 4) a) (10 pts) Below IS the phase diagram for sulfur. Remembenng Clausms Clapyeron, create a P vs. T equation for the temperature of the solid-solid transition between solid rhombic and solid monoelinie sulfur. Write the Clausius Clapyeron equation for the two solid phase tansifion '— assume AH and AV are constants. Integrate your equation between T] and T2 €33: +7) at?” av , 5 5a” :3 ail} «i ' Whitmtnmlig) I Fa” it ('3 i?“ ’t . t 2 i=2 5.2.3 3“} .I:'_. :- ET 7:: MM. 3* (7' «33 It 'wm.-..fi.._ m b)(5pts) From your equation and the sign of the slope ofyour b mug“; _ elow is this transition code or .13... . . _.._ ._ .mh Ifyou want SET UP BUT DO NOT SOLVE {to save time. 5) Assuming gaso e is octane mfi'fi‘rmrma’i boiling point (760n1rrfl-Ig) at 1250 (398K) and AHvap= +33.6 kJ/mol a) (10 pts) What is the vapor pressure of octane (MW = 114.2 gfmoi) at a summer temperature of 105F(314 K)? I R) w ‘ ‘ 6 A ? AW? meta 4) )fi-{a} fl? 3’53 “ 8:3»: Watt; Eiszezgissgi . We You are storing gasoline in a 1,000,000 gallon [1.0 US gallon = 3.78 liters) abeve~ground storage tank. The tank has been pumped out, but some small amount of liquid remains at the bottom of the task (assume the vapors are still in equilibrium with the liquid.) b) (10 pts) How many galions of liquid octane are left in the gas phase? ( him: assume the vapors are an ideal gas and calculate the number of moies present. Densifiof Hquid octane = 0.703 glee 1000 cc=1.01iters. u U ” E3 (5 ((01,332. 3’73 we” 74 ~ fie» -— -« -- K gt #63711?! #23343; um Va is; 07% (@493? g a 5&2 ' iffyw {a a c) (Spts) IN CLASS we suggested a way this waste of fuel could be eliminated by the construction of the tank. .. what was it? This might be used for personal car gas tanks to preggn‘; vapor loss when gm“ fiiiing your tank. I x” Haws 0%» @119 in me" away a i " ' igataém wig; {was DO # 6 or # 8 (Note #8) Cross off the one you do not want graded. Ifnone is marked we will grade #8 6) Consider the equilibrium N204 (g) <=> 2 N02 (:3) WW'WWMW‘e-x , 'PSW ubknown amount of N20;1 1h aunt of If?) The system comes to by)“ WW I eqtfilibflri— a) Sp“’i‘s)'i§sing the Gibbs phase rule compute the degrees of fieedoxn F 5= tic—ow; Ewiw“ J? Memes. 5““ 1362 WWZIWBJJ +3“ Shfi’v’lfitJC‘: Leggy-93%, i: e" gs if; b) (Spts) Explain how you could make F=O Be specific “Measuie mam of the knife.” F: x and; we mewmw Meeker? M35 (meta sisal "r as» [Wag WWW? 05‘ c) (SPts) Whatdoes“invariant”or7E=O w£ U07” W fieifis e?“ if M“ lwwfiififififisa age-zones “A “W 673‘ 7)(lSpts)Extractiou is a common technique in organic chemistry lab. Consider this experiment I2 is mixed with both water and CCl4. the system is shaken and allowed to settle and separates into two layers since CCl4 and H20 do not mix, but the Ig dissolves to some extent in both. The “extraction coefficient” is given by K = X (12 in CCL4) X (12 in water) AM? was fig: fifth 72mm; Den've this experimental relationship by doing the following: ‘$, é? - Write [.L for [2 dissolved in water (assume ideal mixtur A135?!" Write p. for £2 dissolved in CCi4 (assume ideal ' e I 3 ii :3 . PM)! the condition for e bn 7 iii vary mth temW-—mmfl\\ ’7 "s: «53/ a f‘ngefis r me kids if?) Q?! we." ,3 s/ber flifige’im—f’v’g “F géffl‘t Riel? 3 waffle; é}: ‘5'; " __ @5232?) g; fl‘i’i’ X ‘ jet/fl ‘* e w e C, De MW ____ .. Me“; i m 8) (1 Spts —-— one point each) 011 the following drawings match the following items with the indicated points. Some circles can be left biank. A) region of complete solubility B) highest temperature where both liquids completely mix C) TIE LINE D & E) two solutions formed at X= 0.6 @ 700 F 8:. G) two solutions formed at X: 0.3 @700 For the solutions formed at X: 0.7 which A) eutectic B) liquid region C) melting point of A D) two phase (solid + liq) region E) two phase {solid + solid) legion Compute ( give a rough numerical answer) 7 for pt 1 based on Raouit’s iaw // iii-'97; 20 Which is closer to the ideal case? 5 M 'y for pt 1 based on Henry’s law WEAR pm. [5; pm" cm) at? Moi-Fa; eximo ”' 3W ' "M $5 For Mew. “Te 76:5” 22! 6751’?“ Jame am fee“ 4mg- ...
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key_exam_3_F06 - GRADE I = % 1) a)(IOpts) One mole of...

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