(Solved):   Consider the synthesis of hydrogen iodide from molecular hydrogen and iodine. At equilibri ...

 

Consider the synthesis of hydrogen iodide from molecular hydrogen and iodine. At equilibrium, a vessel contains a mixture of \( \mathrm{I}_{2} \) (purple), \( \mathrm{H}_{2} \) (colorless) and \( \mathrm{HI} \) (colorless). The value of the equilibrium constant \( \mathrm{K}_{\mathrm{c}} \) for this reaction is 56 at a temperature of 200 kelvin. Answer parts a-d. Label your answers. \[ \mathrm{H}_{2}(g)+\mathrm{I}_{2}(g) \rightleftharpoons 2 \mathrm{HI}_{(g)} \] a) If the purple color of the mixture fades as the temperature is raised, is the reaction forming HI exothermic or endothermic? (4pts) b) A flask is immersed in a constant-temperature bath maintained at 200 kelvin. The flask initially contains the following: \( \left[\mathrm{H}_{2}\right]=0.024 \mathrm{M},\left[\mathrm{I}_{2}\right]=0.036 \mathrm{M} \) and \( [\mathrm{HI}]=0.15 \mathrm{M} \). Will the concentration of \( \mathrm{HI} \) increase or decrease as equilibrium is established? show work \[ \text { ( } 6 \mathrm{pts}) \] c) What is the value of \( \mathrm{K}_{\mathrm{c}} \) for the following reaction conducted at 200 kelvin? \[ \mathrm{HI}(g) \rightleftharpoons 1 / 2 \mathrm{H}_{2}(g)+1 / 2 \mathrm{I}_{2}(g) \] (4pts) show work