Chapter 15, Problem 82IAE

The decomposition of salicylic acid to phenol and carbon dioxide was carried out at 200.0°C, a temperature at which the reactant and products are all gaseous. A 0.300 g sample of salicylic acid was introduced into a 50.0 mL reaction vessel, and equilibrium was established. The equilibrium mixture was rapidly cooled to condense salicylic acid and phenol as solids; the ${\text{CO}}_{\text{2}}$ (g) was collected over mercury and its volume was measured at 20.0 °C and 730 mmHg. In two identical experiment, the volumes of ${\text{CO}}_{\text{2}}$ (g) obtained were 48.2 and 48.5 mL, respectively. Calculate $K_e$ for this reaction, for pressure in atmospheres.