Nernst's potential of K+:

Ans. C. - 90. (Ref. Guyton 11th/pg. 565; Ganong 23rd/pg. 7-8. Table 1-1.)# Nernst potentialsfor K+ is ?90 mv; for Na+ is +60 mv, and for Cl? is ?70 mv.Nernst's potential# In the resting state, the membrane is primarily permeable to K+ and, therefore, the resting membrane potential is close to the equilibrium potential for K+.# A potential that exactly opposes movement of an ion is called the Nernst potential for that ion; the equation for this is the following :EMF (mV) = +-61.5 x log .where EMF is the Nernst potential in millivolts on the inside of the membrane.# The resting membrane potential is calculated with the Goldman equation.IonConcentration (mmol/L of H2O) Inside CellOutside CellEquilibrium Potential (mV)Na+15.0150.0+60K+150.05.5-90CI-9.0125.0-70Concentration of Some Ions Inside and Outside Mammalian Spinal Motor Neurons.