Question

At 37 °C the concentration of Fe3+ inside a cell is 0.092 M and outside is 0.012 M. The cell membrane is permeable to Fe3+. What potential difference in volts would have to exist across the membrane for Fe3+ to be in equilibrium at the stated conditions? Give you answer as the absolute value of the potential difference in volts.

Answer 1

We are given with
T = 37 C
F3+ concentration inside = 0.092 M
Fe3+ concentration outside = 0.012 M
The formula is
E = RT/zF x [X]out/[X]in
When T = 37 C,  RT/F = 60 mV
E = 60/3 (0.012/0.092)
E = 2.61 mV