41. Solution to Chemistry Problem

1. 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

OPTION 1
State
Solid state
T, K 268.2 269.2 270.2 271.2 272.2
P, Pa 401.2 437.2 475.9 517.2 533.2
Liquid state
T, K 269.2 272.2 273.2 275.2 278.2 283.2 288.2
P, Pa 505 533.2 573 656 760 982 1600
Conditions
M=18
P=40.5*105 Pa
dsolid=918
dliq=1000