how do i calculate a concentration ratio of oxidised to reduced cytochrome c Fe2+ to Fe3+

given at 25 C and pH7
E(mV) as 100
and absorbance at 550nm as 1.5

E is relative to standard hydrogen electrode

i don't know how im supposed to calculate it from this data

please help

To calculate the concentration ratio of oxidized (Fe3+) to reduced (Fe2+) cytochrome c, you can use the Nernst equation. The Nernst equation relates the electrode potential of an electrochemical cell to the concentration of the redox species involved.

In this case, the Nernst equation for the redox couple Fe3+/Fe2+ is:

E = E° - (RT/nF) * ln([Fe2+]/[Fe3+])

Where:
- E is the electrode potential (in volts)
- E° is the standard electrode potential (in volts) measured relative to the standard hydrogen electrode
- R is the gas constant (8.314 J/(mol·K))
- T is the temperature in Kelvin (25°C = 298 K)
- n is the number of electrons transferred in the redox reaction (typically 1 for a Fe3+/Fe2+)
- F is Faraday's constant (96,485 C/mol)
- [Fe2+] and [Fe3+] are the concentrations of Fe2+ and Fe3+ respectively

To solve for the concentration ratio, we need to rearrange the Nernst equation:

[Fe2+]/[Fe3+] = e^((E° - E) * (nF/RT))

Given the information you provided:
- E° = 100 mV = 0.1 V (since the given potential is already in millivolts)
- E = 0.1 V
- R = 8.314 J/(mol·K)
- T = 298 K
- n = 1 (since Fe3+/Fe2+ transfers 1 electron)
- F = 96,485 C/mol

Plugging in these values, we can calculate the concentration ratio:

[Fe2+]/[Fe3+] = e^((0.1 - 0.1) * (1 * 96,485 / (8.314 * 298)))

Since the value (0.1 - 0.1) equals zero, the concentration ratio simplifies to:

[Fe2+]/[Fe3+] = e^(0)

And any value raised to the power of 0 is always equal to 1. Therefore, the concentration ratio of Fe2+ to Fe3+ is 1.

In summary, based on the given data and using the Nernst equation, the concentration ratio of oxidized to reduced cytochrome c (Fe3+ to Fe2+) is 1.