Final answer:
To calculate the energy change for the reaction K(g) + I(g) → K+(g) + I−(g), the ionization energy of potassium (endothermic) and the electron affinity of iodine (exothermic) need to be considered. Since the values are not provided, no numerical answer can be given; the result is the sum of the positive IE and the negative EA. The answer lies in one of the provided options.
Step-by-step explanation:
The student has asked to calculate the energy change for the reaction K(g) + I(g) → K+(g) + I−(g). To solve this problem, we need to consider the ionization energy (IE) required to remove an electron from the potassium atom and the electron affinity (EA) associated with the iodine atom gaining an electron.
The ionization of potassium (IEK) is an endothermic process, therefore energy is absorbed, and the IE value is positive:
K(g) → K+(g) + e−
energy required = IEK
The electron affinity of iodine (EAI) is an exothermic process, where energy is released when an electron is added to the iodine atom:
I(g) + e− → I−(g)
energy change = EAI
To find the total energy change for the reaction, we add the ionization energy of potassium and the electron affinity of iodine:
Total energy change = IEK + EAI
Since the values for IE and EA are not provided in the question, we cannot give a numerical answer. However, the process to find the energy change involves subtracting the EA value (which is negative due to exothermic release) from the IE value (which is positive). The final answer lies in one of the options provided (A, B, C, D, or E).