Solution Found!
Answer: Using Entropy Data and ConceptsUsing the
Chapter 6, Problem 8P(choose chapter or problem)
Using the appropriate table, determine the indicated property for a process in which there is no change in specific entropy between state 1 and state 2.
(a) water, \(p_{1}=14.7 \mathrm{lbf} / \mathrm{in} .^{2}, \ T_{1}=500^{\circ} \mathrm{F}, \ p_{2}=100 \mathrm{\ lbf} / \mathrm{in} .^{2}\) Find \(T_{2}\) in \({ }^{\circ} \mathrm{F}\).
(b) water, \(T_{1}=10^{\circ} \mathrm{C}, \ x_{1}=0.75\), saturated vapor at state 2. Find \(p_{2}\) in bar.
(c) air as an ideal gas, \(T_{1}=27^{\circ} \mathrm{C}, \ p_{1}=1.5 \mathrm{bar}, \ T_{2}=127^{\circ} \mathrm{C}\). Find \(p_{2}\) in bar.
(d) air as an ideal gas, \(T_{1}=100^{\circ} \mathrm{F}, \ p_{1}=3 \mathrm{\ atm}, \ p_{2}=2\) atm. Find \(T_{2}\) in \({ }^{\circ} \mathrm{F}\).
(e) Refrigerant 134a, \(T_{1}=20^{\circ} \mathrm{C}, \ p_{1}=5 \mathrm{\ bar}, \ p_{2}=1\) bar. Find \(v_{2}\) in \(\mathrm{m}^{3} / \mathrm{kg}\).
Questions & Answers
QUESTION:
Using the appropriate table, determine the indicated property for a process in which there is no change in specific entropy between state 1 and state 2.
(a) water, \(p_{1}=14.7 \mathrm{lbf} / \mathrm{in} .^{2}, \ T_{1}=500^{\circ} \mathrm{F}, \ p_{2}=100 \mathrm{\ lbf} / \mathrm{in} .^{2}\) Find \(T_{2}\) in \({ }^{\circ} \mathrm{F}\).
(b) water, \(T_{1}=10^{\circ} \mathrm{C}, \ x_{1}=0.75\), saturated vapor at state 2. Find \(p_{2}\) in bar.
(c) air as an ideal gas, \(T_{1}=27^{\circ} \mathrm{C}, \ p_{1}=1.5 \mathrm{bar}, \ T_{2}=127^{\circ} \mathrm{C}\). Find \(p_{2}\) in bar.
(d) air as an ideal gas, \(T_{1}=100^{\circ} \mathrm{F}, \ p_{1}=3 \mathrm{\ atm}, \ p_{2}=2\) atm. Find \(T_{2}\) in \({ }^{\circ} \mathrm{F}\).
(e) Refrigerant 134a, \(T_{1}=20^{\circ} \mathrm{C}, \ p_{1}=5 \mathrm{\ bar}, \ p_{2}=1\) bar. Find \(v_{2}\) in \(\mathrm{m}^{3} / \mathrm{kg}\).
ANSWER:a.)
Step 1 of 5
We have to determine the temperature of the water in state 2 for a process in which there is no change in specific entropy between state 1 and state 2.
The temperature and pressure of water in state 1 for the given process are
oF
14.7 lbf/in2
From table A-4 E in the book, the entropy of the water in state 1 is given by
Btu/lb
oR
Interpolating with in Table A-4E at
lbf/in2 the temperature
of the water in state 2 is given by
oF
Therefore, the temperature of the water in the state 2 is 1017 oF .
b.)