Question

An unknown potential difference exists between the inner and outer surfaces of the membrane of a cell. The inner surface is negative relative to the outer surface. If 2.5 x 10-20 J of work is needed to eject a positive Calcium ion (Ca2+) from the interior of the cell, what is the value of the potential difference?

Answer 1

V*q=work
q= 2*1.6E-19 coulombs

Answer 2

doesnt vq = - work ?...signs are important

since work = -u, and u = vq