Saturated liquid water at 1.0 MPa is throttled adiabatically to a pressure of 0.4 MPa. If the change in kinetic energy is negligible, the percentage of water that evaporates during this throttling process will be
A)0.0%
B)3.8%
C)24.8%
D)7.4%
E)100%

Question

Quizplus · Accepted Answer

Solved by EES Software. Solutions can be verified by copying-and-pasting the following lines on a blank EES screen. 
P1=1000 "kPa"
x1=0
P2=400 "kPa"
"Quality represents the percentage of water that evaporates:"
h1=ENTHALPY(Steam_IAPWS,x=x1,P=P1)
x2=QUALITY(Steam_IAPWS,h=h1,P=P2)
"Some Wrong Solutions with Common Mistakes:"
v1=VOLUME(Steam_IAPWS,x=x1,P=P1)
W1_x2=QUALITY(Steam_IAPWS,v=v1,P=P2) "Assuming the volume to remain constant"
u1=INTENERGY(Steam_IAPWS,x=x1,P=P1)
W2_v2=VOLUME(Steam_IAPWS,u=u1,P=P2) "Assuming u=constant"

Saturated Liquid Water at 1