Question

The Extracellular conectration of a chloride ion is 131 mmol/L. The equilibirum concentration is -68.8 mV. Using the Nernst equation calculate the intracellular concentration.

E = RT/zF * ln ( Xout - Xin )

R= 8.314
T= 298 K
z = 1
F = 96487

I know that the answer is 9 mmol/L I just can't work the problem out myself. It would be helpful to see how one would solve for intracellular concentration variable first.

Answer 1

The Extracellular conectration of a chloride ion is 131 mmol/L. The equilibirum concentration is -68.8 mV. Using the Nernst equation calculate the intracellular concentration.

E = RT/zF * ln ( Xout - Xin )

R= 8.314

T= 298 K

z = 1

F = 96487

I know that the answer is 9 mmol/L I just can't work the problem out myself. It would be helpful to see how one would solve for intracellular concentration variable first.

Substituting values in above equation,

-68.8×10^-3 = [8.314×298/(-1)× 96487] × ln(131/X_in)

-68.8×10^-3 = -0.0256 × ln(131/X_in)

ln(131/X_in) = 2687.5×10^-3

ln(131/X_in) =2.687

Xin = 8.919 mMol/L