Thermodynamics of a solid-state reaction. The following electrochemical cell is reversible at 1 000 K in an atmosphere of flowing O2(g):19

(a) Write a Nernst equation for each half-cell. Write the net reaction and its Nernst equation. The activity of O2(g) is the same on both sides, and the activity of F- is the same on both sides, governed by F- ions diffusing through CaF2(s). Show that the observed voltage is E° for the net reaction.
(b) From the relation ˆ†G° = -nFE° , find ˆ†G° for the net reaction. Note that 1 V = 1 J/C.
(c) The cell voltage in the temperature range T = 900 to 1 250 K is E(V) = 0.122 3 + 3.06 × 10-5 T. Assuming that ˆ†H° and ˆ†S° are constant, find ˆ†H° and ˆ†S° from the relation ˆ†G°= ˆ†H° - Tˆ†S°

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+0.1529 V Intimate mixture of MgF2is) and MgO(s) Intimate mixture of MgF2(s) MgAI204(s) and AlOg(s) CaF2(s)