Chapter 16, Problem 35QAP

In the laboratory, POCl₃ (phosphorus oxychloride) is used in the manufacture of phosphate esters, which are used in flame retardants and pesticides. It can be prepared by the following reaction at 25°C:

$2{\text{PCl}}_3\left(g\right)+{\text{O}}_2\left(g\right)\to 2{\text{POCl}}_3\left(g\right)$

$\Delta H°=-572\text{kJ};\Delta G°=-518.7\text{kJ}$(a) Calculate ΔS°. Is the sign reasonable?

(b) Calculate ΔS° for POCl₃.

(c) Calculate for POCl₃.