Final answer:
The estimation of reduced volume, reduced enthalpy, and reduced entropy for oxygen at 150 K and 20 bar involves using the corresponding states principle with generalized correlations and potentially the ideal gas or van der Waals equation. The accuracy of these methods could be assessed by comparing the estimates to the actual known temperature of oxygen under the conditions provided.
Step-by-step explanation:
Estimation of Thermodynamic Properties for Oxygen
The question asks to estimate the reduced volume (vr), reduced enthalpy (hr), and reduced entropy (sr) for oxygen at 150 K and 20 bar using generalized correlations. These calculations require the use of non-ideal gas equations of state because under these conditions, oxygen cannot be assumed to behave ideally due to the high pressure and low temperature.
To solve this, one would typically use the corresponding states principle, which provides generalized correlations for non-ideal gases. The properties of oxygen can be estimated by using its critical properties (Tc and Pc) and the dimensionless reduced properties (Tr and Pr).
For the ideal gas estimate, one would use the ideal gas law (PV=nRT), and for the van der Waals estimate, one would input the given values into the van der Waals equation (P + a(n/V)^2) * (V/n - b) = nRT), where 'a' and 'b' are substance-specific constants. To judge the accuracy of the methods, one could compare the estimated temperatures with the actual temperature of the oxygen under the given conditions.
When evaluating the accuracy of methods, both the ideal gas equation and van der Waals equation may have limitations. The vs. V graph or Boyle's law equation would not be relevant for this estimation as they relate to the relationship between pressure and volume, not thermodynamic properties at specific temperatures and pressures.