Determine the equilibrium constant, Keq, for the reaction


5.3 10–19
18.30
1.7 1054
1.9 1018
5.7 10–55

i have tried this but get the wrong answer. i have the half-rxn and fugured out E=0.536. then used eq
dG=-nFE, followed by dG=-RTInK. PLS HELP

I responded to this recently by saying you needed to clarify what these numbers are. I have no idea what they mean. That may explain why no one has answered you because no one can figure out to what these numbers refer.

right then, numbers are-

Br2 + 2e- = 2Br E=1.065V
I2(s)+ 2e- = 2I- E=0.536V
i have placed both these numbers into eq- Ecell= Ered(cathode)-Ered(anode)
but for every combination, using the before mentioned eq, i cannot get any answers that they offer.
If E i get either +/- 1.601 or +/- 0.529. these put into eq 2- dG=-nFE (n=moles, F-96485, E=? Above)
then putting that into eq 3- dG=-RTInK (with R=8.314, and T=298) to find K. I just cant get their answers!?

To determine the equilibrium constant, Keq, for a reaction using the Nernst equation, you need the half-reaction, the standard reduction potential (E°), and the number of electrons transferred (n).

Given that you have the half-reaction and the calculated standard reduction potential (E = 0.536 V), let's go through the steps to find Keq using the equation: ΔG = -nFE = -RT ln Keq.

Step 1: Determine the number of electrons transferred (n)
Based on the half-reaction, count the number of electrons on the reactant and product sides. The difference is the number of electrons transferred. For example, if one side has 4 electrons and the other has 2, then n = 2.

Step 2: Calculate ΔG using the equation: ΔG = -nFE
Here, F is the Faraday constant (9.6485 x 10^4 C/mol). Plug in the values for n and E: ΔG = - (2) * (9.6485 x 10^4 C/mol) * (0.536 V).

Step 3: Convert ΔG to ΔG° using the formula: ΔG = ΔG° + RT ln Q, where ΔG° is the standard free energy change at equilibrium and Q is the reaction quotient.
As the reaction is at equilibrium, ΔG = 0, so we have ΔG° = - RT ln Keq. Rearrange the equation to solve for ln Keq: ln Keq = -ΔG° / (RT).

Step 4: Evaluate ln Keq using the calculated values
R is the ideal gas constant (8.314 J/(mol·K)) and T is the temperature in Kelvin. As this calculation involves temperature, ensure that you convert Celsius to Kelvin by adding 273.15. Substitute the values into the equation: ln Keq = -ΔG° / (RT).

Step 5: Solve for Keq by taking the antilog of ln Keq.
Once you have the value for ln Keq, take the antilog (exponential function) to solve for Keq. Remember to use the same base for the antilog function that was used for the natural logarithm (ln). Usually, scientific calculators have an "e^x" or "exp" button to calculate the antilog.

By following these steps, you should be able to find the correct value for Keq.