The equilibrium constant K p (in atm) for the dissociation reaction of Cl 2
Cl 2 2Cl
was measured as a function of temperature (in K). A graph of ln K p versus 1/T for this reaction gives a straight line with a slope of -1.352 × 10 4 and an intercept of 14.51.
-From these data, which of the following statements is true?

Question

The equilibrium constant K p (in atm) for the dissociation reaction of Cl 2 
 Cl 2  2Cl
was measured as a function of temperature (in K). A graph of ln K p versus 1/T for this reaction gives a straight line with a slope of -1.352 × 10 4 and an intercept of 14.51.
-From these data, which of the following statements is true?

Quizplus · Accepted Answer

The slope of the graph for ln K vs 1/T is equal to -ΔH/R, where ΔH is the enthalpy of the reaction and R is the gas constant. Since the slope is negative, ΔH must also be negative. Therefore, the reaction is exothermic. The question asks for the opposite, so the correct answer is A) The reaction is endothermic. The value of the slope (-1.352 × 10^4) also confirms this as it is a large negative value. We cannot determine the spontaneity of the reaction from this information.

The Equilibrium Constant Kp (In Atm) for the Dissociation Reaction

The Equilibrium Constant K_p (In Atm) for the Dissociation Reaction