For an ideal gas undergoing a process, the change in specific entropy can be calculated using the relation s2 - s1 = Cp * ln(T2/T1) - R * ln(P2/P1). Air is compressed from an initial state of 100 kPa and 27 degrees Celsius (300.15 K) to a final state of 600 kPa and 67 degrees Celsius (340.15 K). For air, Cp = 1.005 kJ/kgK and R = 0.287 kJ/kgK. Calculate the change in specific entropy.
Explanation
The change in specific entropy for an ideal gas depends on both the change in temperature and the change in pressure. The formula s2 - s1 = Cp * ln(T2/T1) - R * ln(P2/P1) accounts for both effects. It's crucial to use absolute temperatures (Kelvin) in the calculation.
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