Question

2. (11 marks) a) At 400 °C, ammonium iodide decomposes in the following endothermic reaction: NH41(s) + NH3(g) + HI(g) Kp = 0.215 at 400 °C. Write the equilibrium expression for this reaction. 15.0 g of NH4I was placed in an empty 3.0 L flask and heated to 400 °C. What is the partial pressure of NH3 in the flask once the reaction has reached equilibrium? How would the following changes to the equilibrium mixture affect the number of moles of NH3 in the flask and the value of K, once equilibrium is re-established? (Use increase, decrease or stay the same.) Change Effect on moles of NH3 Ke value Increase temperature Increase volume of flask Remove half of HI gas