The electrical potential difference necessary for a single ion to be at equilibrium across a membrane is best described by the:

Ans. D. Nernst equationa. The Nernst equation calculates the membrane potential that develops when a single ion is distributed at equilibrium across a membrane.b. The Goldman equation gives the value of the membrane potential when all permeable ions are accounted for.c. The van't Hoff equation calculates the osmotic pressure of a solution.d. Fick's law refers to the diffusional movement of solute. The permeability coefficient accounts for several factors that determine the ease with which a solute can cross a membrane