Useful numbers: kB=1.38 x 10-23 J/K (Boltzmann's constant)
q=1.6 x 10-19 C (charge on a positive ion with charge +1)
If the concentration of sodium inside a cell is 12 mM, and the concentration outside the cell is 162 mM, find the equilibrium potential for sodium. The temperature is 300 K. If the actual potential difference across the cell membrane is -90 mV, does sodium "want" to flow in or out?