3. Based on the dependence of the saturated vapor pressure on the temperature and density of a given substance A (ds and df in kg/m3) at the triple point (tp):
1) plot a graph of lgP versus 1/T;
2) determine the coordinates of the triple point from the graph;
3) calculate the average heat of evaporation and sublimation;
4) approximately determine the boiling point of the substance at normal pressure;
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 p, Pa;
8) calculate the change in entropy, Gibbs and Helmholtz energy, enthalpy and internal energy for the sublimation process of 1 mole of the 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) Tntk, p= 1.013 x 105 Pa;
c) Tntk, ptr.t

No. var 3

Solid state
T, K 55 58 60 62 63 64
P, Pa 1480 3999 7331.5 11997 14663 17329

Liquid state
T, K 60 64 66 67.8 69 71
P, Pa 10115 17329 22394 27993 31992 39990

Conditions M=28 P=500*105 Pa
dsolid=1026
dliq=808