Problem Set #30: Thermodynamic Property Calculations

University:
The Pennsylvania State University
Course:
CHEM 450 | Thermodynamics
Academic year:

2024
Views:

119

Pages:

2
Author:

Alexis H.

Problem Set #30 Assigned: March 20, 2024 Due: March 22, 2024 at 2:30 pm 1. The vapor pressure of dichloromethane at 24.1 °C is 0.533 bar and its enthalpy of vaporization is 28.7 kJ/mol. Find the temperature that would be associated with a vapor pressure of 0.700 bar. 2. Benzene freezes at 5.5 °C at 1 atm of pressure. Its mass density rises from 0.879 g/cm3 to 0.891 g/cm3 upon freezing. Also, its enthalpy of fusion is 10.59 kJ/mol. Estimate the freezing point of benzene under 1000 atm of pressure. 3. The vapor pressure of benzene between 10 °C and 30 °C fits the expression: Log(p/Torr) = 7.960 – (1780K)/T. Find the enthalpy of vaporization and the standard boiling point for benzene. Note that “standard” means at 1.00 bar and 298.15 K. 4. A polynomial fit to the measurement of the total volume of a binary mixture of A & B fits to the expression: V = 987.93 + 35.6774x – 0.45923 x2 + 0.017325 x3 V = V/cm3 x = nB/mol nB is the number of moles of the second component, B. Derive an expression for the partial molar volume of A ,which is called VA. Derive an expression for the partial molar volume of B, which is called VB. 4 1 In 2 0.879 P 0.533bar 0.273 3452 ah 294.1 p p 31.2 C 7 4 87.67 t 1000atm If T T 1atm 27 655 T 281.8 k or 0.891 1 103 T 278.657 3.15102 T 278.657 3.1914 7 9 105 2 1 Tz 304.2k 7 f ΔV 88.86 87.67 1.19 Tz 8.3103 p v 88.86 P2 0.700bar ΔH 28.7KUMol T 24.1 273 297 I K in 833 f p or T 278.65 101.325 8.6 C 3 log Irr log Po ΔvapH 2303K ΔvapH 7.960 Is3 1780 1780 2.303 8.314 Draph 34.082 KUmol 4 VA VB 2 35.6774 0.91846 0.051975 22.5749 1.13784 0.030692 0.009363 log18h 7.960 28808 7.960 178,0 1780 17,80 7.960 2.8808 T 5 99 T 350.5k