Practice: Given the following standard reduction potentials, determine Ksp for Hg2Cl2(s) at 25 °C.
Hg22+ (aq) + 2 e– →. 2 Hg (l) E°red = + 0.789 V
Hg2Cl2 (s) + 2 e– →. 2 Hg (l) + 2 Cl – (aq) E°red = + 0.271 V
Cell Potential, Gibbs Free Energy and the Equilibrium Constant deal with the spontaneity of electrochemical cells
The Triangle Diagram
Concept #1: The relationship between these 3 variables and spontaneity can be observed through the Triangle Diagram.
Example #1: Calculate the standard cell potential for the following reaction if 10 moles of electrons are transferred.
P4 (s) + 5 O2 (g) → P4O10 (s)
Practice: What is the value of the cell potential for the 4 electron transfer reaction below if the equilibrium mixture contains 0.255 M of CH4, 1.10 M CO2, 0.388 M CO and 0.250 M H2 at 25ºC?
CH4 (g) + CO2 (g) ⇌. 2 CO (g) + 2 H2 (g)
Practice: Given the reaction: 2 Cl2 (g) + 2 H2O (g) ⇌ 4 HCl (g) + O2 (g) Kp = 7.5x10-2, calculate the Gibbs Free Energy change for the reaction below at 30ºC.
8 HCl (g) + 2 O2 (g) ⇌ 4 Cl2 (g) + 4 H2O (g)
