Calculate the initial emfa of this cell. Cl2|cl-|pt||cr3+|cr

Answer 1

To calculate the initial electromotive force (emf) of the cell, we need to know the standard reduction potentials of the half-reactions involved.

The half-reaction for the Cl2/Cl- couple is:

Cl2 + 2e- -> 2Cl- E° = +1.36 V

The half-reaction for the Cr3+/Cr couple is:

Cr3+ + 3e- -> Cr E° = -0.74 V

The emf of the cell can be calculated using the Nernst Equation:

Ecell = E°cell - (0.0592 V/n) * log(Q)

where E°cell is the standard cell potential, n is the number of moles of electrons transferred, and Q is the reaction quotient.

Here, the reaction quotient (Q) for the cell is given by:

Q = ([Cr3+]/[Cl-]^2)

Since the concentration of Cl- is 1M (because it is a standard state), we only need to determine the concentration of Cr3+.

Assuming the concentration of Cr3+ is 1M, we can calculate the emf of the cell as follows:

Ecell = E°cell - (0.0592 V/3) * log(1/[Cl-]^2 [Cr3+])
= E°cell - (0.0592 V/3) * log(1/(1)^2 [1])
= E°cell - (0.0592 V/3) * log(1/1)
= E°cell - (0.0592 V/3) * log(1)
= E°cell

Therefore, the initial emf of this cell is equal to the standard cell potential (E°cell), which needs to be provided in order to calculate the exact value.