UA Chemical & Biological Engineering - CHE 255 Spring 2025
Page 11
Put your 'cheat sheet' under your exam and turn them in together.
Some useful data tables are included on the final two pages of this exam!
1. (30 points) A piston-cylinder assembly contains 10 mol of water at 400 Kand 0.5
bar. The system is compressed isothermally until all the water is condensed. What
is the final pressure (in bar) and volume (in L) of the system at the final state? What
is LiU (in kJ) for this process?
2 (u)
--
s,~-re i (v) S-rA--1€
IO MOL.
ID MC'\-
()
YCOK '-fOOK.
\
?
r 0 -~ 6~ "
'? ?.
\J
?. 7
L)
1
~0
t:=e.11'-1 -r,._B<.£ \ .p'l- 0~'.} ~1
\I -=-
,
t,b . I~, t-./~ v,,
&,
=- o .ottl22- 1.,./~
I
L) I :: "15 _l~fo~ 1../,.,,,,,__ ½, = Cj -~"f "<.. '-1MA-
AU -=- IO ~(1;/1/,;. q ·$0,~fo - ~ ·CJ b~) "J/,t,ts,._ AL) :=
AU" t 3G:.- 3b8 ){1o') ::- [- 3b3 .Gol? id I
....
, UA Chemical & Biological Engineering - CHE 255 Spring 2025
Name: ~ February 13, 2025 Midterm #1 Page 12
2. (30 points) Water exists as a vapor-liquid mixture at 0.5 bar. The enthalpy of the
water was calculated to be h = 20 kJ/mol. What is the temperature of the system
(in K) and what is the quality (x) of the water (i.e., steam)?
\.JzD e Vt..£ C,.~ SA2
~ -r...S<.£ I[~ 35'-j .'-/-:/- K_]
IJ1 \ >< ot: v.Af>dl 4- t-\ (iJ.\J ( b' Sui'" HCl...t RAC.S v~~;V •
D,ve;"-.) V)~ 2-0 ~)~ sc rruusr6G""Tl-lf4-,
X == f-;ta.. F~'-- v~
=- ~u.7:'f
h., " '-11 . blo '1 v.J/,.,,._ n1.--" re, .134 i<J /..,._
zo -: 41 . to5<-/ >C .... (,- ~; eo., as
2,0 :: tr=,. .<oSlf )(' -t- (c, . I ~g - ~. l 3g K"
13.~ " ' 41.€/'lx )<::: l3.1%S - ~~38°r)
<-fl -~lq L
Page 11
Put your 'cheat sheet' under your exam and turn them in together.
Some useful data tables are included on the final two pages of this exam!
1. (30 points) A piston-cylinder assembly contains 10 mol of water at 400 Kand 0.5
bar. The system is compressed isothermally until all the water is condensed. What
is the final pressure (in bar) and volume (in L) of the system at the final state? What
is LiU (in kJ) for this process?
2 (u)
--
s,~-re i (v) S-rA--1€
IO MOL.
ID MC'\-
()
YCOK '-fOOK.
\
?
r 0 -~ 6~ "
'? ?.
\J
?. 7
L)
1
~0
t:=e.11'-1 -r,._B<.£ \ .p'l- 0~'.} ~1
\I -=-
,
t,b . I~, t-./~ v,,
&,
=- o .ottl22- 1.,./~
I
L) I :: "15 _l~fo~ 1../,.,,,,,__ ½, = Cj -~"f "<.. '-1MA-
AU -=- IO ~(1;/1/,;. q ·$0,~fo - ~ ·CJ b~) "J/,t,ts,._ AL) :=
AU" t 3G:.- 3b8 ){1o') ::- [- 3b3 .Gol? id I
....
, UA Chemical & Biological Engineering - CHE 255 Spring 2025
Name: ~ February 13, 2025 Midterm #1 Page 12
2. (30 points) Water exists as a vapor-liquid mixture at 0.5 bar. The enthalpy of the
water was calculated to be h = 20 kJ/mol. What is the temperature of the system
(in K) and what is the quality (x) of the water (i.e., steam)?
\.JzD e Vt..£ C,.~ SA2
~ -r...S<.£ I[~ 35'-j .'-/-:/- K_]
IJ1 \ >< ot: v.Af>dl 4- t-\ (iJ.\J ( b' Sui'" HCl...t RAC.S v~~;V •
D,ve;"-.) V)~ 2-0 ~)~ sc rruusr6G""Tl-lf4-,
X == f-;ta.. F~'-- v~
=- ~u.7:'f
h., " '-11 . blo '1 v.J/,.,,._ n1.--" re, .134 i<J /..,._
zo -: 41 . to5<-/ >C .... (,- ~; eo., as
2,0 :: tr=,. .<oSlf )(' -t- (c, . I ~g - ~. l 3g K"
13.~ " ' 41.€/'lx )<::: l3.1%S - ~~38°r)
<-fl -~lq L
