Water is boiling at a temperature of 95°C in a pan. If heat is transferred to the pan at a rate of 2 kW, the amount of water that evaporates in 30 minutes is
A)1. 6 kg
B)1.4 kg
C)9.0 kg
D)0.022 kg
E)0.87 kg

Question

Quizplus · Accepted Answer

Solved by EES Software. Solutions can be verified by copying-and-pasting the following lines on a blank EES screen. 
T=95 "C"
time=30*60 "s"
Q=2 "kJ/s"
Q*time=m*h_fg "kJ"
h_f=ENTHALPY(Steam_ IAPWS, x=0,T=T)
h_g=ENTHALPY(Steam_ IAPWS, x=1,T=T)
h_fg=h_g-h_f
"Some Wrong Solutions with Common Mistakes:"
Q*time=W1_m*h_g "Using h_g" 
Q*time/60=W2_m*h_g "Using minutes instead of seconds for time"
Q*time=W3_m*h_f "Using h_f"

Water Is Boiling at a Temperature of 95°C in a Pan