Final answer:
Kc is equal to Kp at 259 degrees Celsius, which is 0.307, assuming that the change in the number of moles of gas in the reaction (Δn) is zero.
Step-by-step explanation:
The student has asked for the value of the equilibrium constant Kc given the equilibrium constant Kp at 259 degrees Celsius. Since the value of Kp is 0.307 at this temperature, to find Kc, we must use the relationship Kp = Kc(RT)Δn, where R is the universal gas constant, T is the temperature in Kelvin, and Δn is the change in the number of moles of gas in the reaction. Given that Δn is not provided in the question, we will assume Δn = 0, which makes Kp equal to Kc directly because (RT)Δn would equal 1. Therefore, at 259 degrees Celsius, Kc would also be 0.307 assuming Δn = 0.