42. Solution to Chemistry Problem

7. Based on the dependence of saturated vapor pressure on temperature and density of a given substance A with molecular weight M in the solid and liquid states (ds and dl in kg/m3) at the triple point (tp):

1. plot a graph of saturated vapor pressure on temperature, indicate the sublimation line, melting line, and evaporation line;
2. plot a graph of ln P on 1/T;
3. determine the coordinates of the triple point from the graph;
4. calculate the average heat of evaporation and sublimation;
5. determine the heat of fusion of the substance at the triple point temperature;
6. calculate dT/dP for the melting process at the triple point temperature;
7. calculate the melting point of the substance at a pressure of P Pa;
8. Calculate the change in entropy, Gibbs and Helmholtz energies, enthalpy and internal energy for the process of sublimation of 1 mole of a substance at the triple point;
9. Determine the number of thermodynamic degrees of freedom at the following values ​​of temperature and pressure: a) Ttr.t, Ptr.t; b) Tn.t.k, P = 1 atm; c) Tn.t.k, Ptr.t. (n.t.k is the normal boiling point). Take the data required for the calculation from the table. № var 7

Solid state
T, K 196 203 213 220
P, Pa 101325 190491 402360 648480

Liquid state
T, K 212 220 223 239 241 242
P, Pa 592751 648480 674824 1005114 1065237 1131722

Conditions M=44 P=750*105 Pa
dsolid=1542 kg/m3
dliq=1510 kg/m3