Solved: Using Entropy Data and ConceptsUsing the

QUESTION:

Using the appropriate table, determine the change in specific entropy between the specified states, in \(\text { Btu/ }\mathrm{lb} \cdot{ }^{\circ} \mathrm{R}\).

(a) water, \(p_{1}=1000 \mathrm{\ lbf} / \mathrm{in} .{ }^{2}, \ T_{1}=800^{\circ} \mathrm{F}, \ p_{2}=1000 \mathrm{\ lbf} / \mathrm{in} .{ }^{2}, \ T_{2}=100^{\circ} \mathrm{F}\).

(b) Refrigerant 134a, \(h_{1}=47.91 \mathrm{Btu} / \mathrm{\ lb}, \ T_{1}=-40^{\circ} \mathrm{F}\), saturated vapor at \(p_{2}=40 \mathrm{\ lbf} / \mathrm{in}^{2}\)

(c) air as an ideal gas, \(T_{1}=40^{\circ} \mathrm{F}, \ p_{1}=2 \mathrm{\ atm}, \ T_{2}=420^{\circ} \mathrm{F},\ p_{2}=1\) atm.

(d) carbon dioxide as an ideal gas, \(T_{1}=820^{\circ} \mathrm{F}, \ p_{1}=1 \mathrm{\ atm},\ T_{2}=77^{\circ} \mathrm{F}, \ p_{2}=3\) atm.