Problem 3a: (Thermodynamic Relations). Estimate the change in specific volume of air, assuming an ideal gas(Pv=RT), using the differential form dv, if the temperature and pressure change from 25 C and 125 kPa to 30 C and 120 kPa.Compare with the change calculated directly from the ideal gas law. The gas constant R=0.287 kJ/kg.K Problem 3b: Derive an expression for the volume expansivity of a substance whose equation of state is given by P=RT/(v-b) – a/(v T). Here a and b are constants. You can use any equation (s) from the chapter to get the expression.

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