Passive Membranes Answer 2

• The charges on both sides are equal, so there is no charge separation across the membrane.
• If there is no charge separation, the potential across the membrane is zero.
• We have another way of checking this answer. From the Nernst equation, we know that we can take the ratio of the concentrations on the inside and out to determine the potential across the membrane.
• From the statement of the problem, we know that the concentrations are equal; thus, their ratio is equal to 1; the log of 1 (to any base) is zero, and so the equilibrium or Nernst potential will be 0 mV; so we have come up with the same answer in a different way.
• Checking answers in this way is a very good idea.