Calculate the cell potential for the following reaction as written at 25.00 °C, given that [Cr2 ] = 0.859 M and [Ni2 ] = 0.0190 M. Standard reduction potentials can be found here.
See your earlier post.
To calculate the cell potential, we need to use the Nernst equation. The Nernst equation relates the cell potential (Ecell) to the standard cell potential (Eºcell) and the concentration of the reactants and products.
The reaction you provided is not mentioned, but you stated that the standard reduction potentials can be found in a separate resource. Therefore, you will need to look up the standard reduction potentials for the half-reactions involved in the reaction. Let's assume the reaction involves the reduction of Cr2+ (aq) and the oxidation of Ni2+ (aq) and the half-reactions are as follows:
Cr2+ (aq) + 2e- -> Cr (s) Eºred = x V
Ni2+ (aq) -> Ni (s) + 2e- Eºred = y V
Now, let's denote the given concentrations:
[Cr2+] = 0.859 M
[Ni2+] = 0.0190 M
To use the Nernst equation, we need to determine the number of electrons transferred (n) in the balanced equation.
In this case, Chromium (Cr2+) is reduced, and two electrons are gained. Nickel (Ni2+) is oxidized, and it loses two electrons. Therefore, the value of n is 2.
Now, the Nernst equation is:
Ecell = Eºcell - (0.0592/n) * log(Q)
where Ecell is the cell potential, Eºcell is the standard cell potential, n is the number of electrons transferred, and Q is the reaction quotient.
The reaction quotient (Q) is calculated using the concentrations of the reactants and products raised to the power of their stoichiometric coefficients. In this case, since the balanced equation is not provided, I cannot give you the exact value of Q. You will need to write the balanced equation for the reaction and calculate the reaction quotient accordingly.
Once you have the balanced equation and the value for Q, you can substitute it into the Nernst equation along with the known values:
Ecell = Eºcell - (0.0592/2) * log(Q)
Using the standard reduction potentials from the given resource and the calculated reaction quotient, you can substitute these values into the equation to find the cell potential.
Note: The temperature is given as 25.00 °C. If the standard reduction potentials provided are at a different temperature, you may need to consider the temperature correction as well.