(Solved): Problem 6 = The phase diagram of ammonia, NH3, can be characterized by the following information. ...

Problem 6 = The phase diagram of ammonia, NH3, can be characterized by the following information. The normal melting and boiling temperatures are 195.2 and 239.82 K, respectively, and the triple point pressure and temperature are 6077 Pa and 195.41 K, respectively. The critical point parameters are 112.8 x 105 Pa and 405.5 K. The heat of capacity at the solid and gaseous states are, respectively, C = 80.8 JK-'mol-1 and C4 = 37.0 JK-mol-1. (a) Make a sketch of the P-T phase diagram (not necessarily to scale) for NH3. Identify the normal melting and boiling points and the triplet point at the graph. (b) Place a point in the phase diagram for 415 K and 130 x 105 Pa and state which and how many phases are present. (c) Find Asm of NH3 heated from 230 K to 260 K at normal pressure. (d) Make a sketch of the Gibbs free energy as a function of temperature (from 0 K to 500 K) for NH3 at P=1 atm. Identify the melting and boiling points. (e) At your sketch in (d) add the Gibbs free energy versus temperature for NH3 at P= 10 atm (by dashed lines). Identify the melting and boiling points.