Hydrogen iodide is formed from its elements according to
H2(g)+I2(g)⇌2HI(g),
and the system is allowed to reach equilibrium at 500 K in a rigid reaction vessel.
Answer the questions below using chemical principles; no numerical calculations are required.
(a) Describe qualitatively what happens to the position of equilibrium when an inert gas (e.g., He) is injected at constant volume while the temperature is held at 500 K.
(b) Explain whether the numerical value of Kp changes under the conditions described in part (a).
(c) Suppose instead that the inert gas is introduced so that the total pressure is held constant (the volume is allowed to change) at 500 K. Describe qualitatively how the position of equilibrium will respond and state whether Kp changes. Justify your answers.