Posted by bekah on Friday, May 2, 2014 at 4:46pm.
Construct a galvanic (voltaic) cell from the half reactions shown below.
Au3+ + 3 e → Au (s) ξo= 1.420 V
Br2 (l) + 2 e→ 2 Br (aq) ξo= 1.087 V
Calculate the equilibrium constant (K) for this cell. Assume that the temperature is 298K.
First, consider what happens to the Nernst equation when the system reaches equilibrium:
ξ = ξo  (RT/nF) ln Q
What is ξ when the system has reached equilibrium? Is there any driving force left?
Remember that ∆G = nFξ.
At equilibrium, ∆G = 0, so ξ = 0, too.
At equilibrium, Q = K, since all reactants and products are present at their equilibrium concentrations.
This simplifies the Nernst equation to:
ξocell = [(RT)/nF] ln K
Now calculate a value for K.
You may need to use scientific notation to record your answer. If so, enter it as: 4E43 which is equivalent to 4x1043

chemistry  Anonymous, Tuesday, March 24, 2015 at 10:31pm
Use second equation
1.420 (1.087)= .333
Use that as cell potential.
R=8.314
T=298
n= 6 mols electrons because you have to multiply the two reactions to get 6 electrons so you can cancel the electrons out
F=96,500
.333= 0.004279lnQ
divide both sides by .00427 to cancel it from the right side
.333/.00427=77.82
77.82=lnQ
enter in calculator 2nd and ln to get e^ (77.82) because you want to get ride of ln from the right side so its pushed to the left side as its inverse of e^ (77.82) and ln cancels out so youre left with Q.
Answer This Question
Related Questions
 chemistry  Use the following pair of reduction halfreactions to design a ...
 chemistry  Consider the following standard reduction potentials of some ...
 Chemistry  Use the data given below to construct a Born  Haber cycle to ...
 chemistry  E degrees (V) A galvanic cell based on the following half reaction s...
 Chemistry  If 0.870 mol of liquid Br2 and 720 mL of 0.958 M aqueous NaI are ...
 chemistry  Which of the following halfreactions would occur at the anode of an...
 Chemistry!  A Galvanic cell runs on the following reaction: Co (s) + Cu2+ (aq...
 Chemistry  Consider two cells, the first with Al and Ag electrodes, and the ...
 chemistry  Using the halfreaction method, balance the redox reaction below. ...
 Chemistry  Given the following halfreactions and associated standard reduction...
More Related Questions