what would happen to the Vm of the cell at 70mV if you add t

what would happen to the Vm of the cell at -70mV if you add twice as much K+ to the extracellular fluid? why?

Solution

The membrane potential is due to differences in the ion concentration on two sides of cell membrane. The inside of membrane is kept negative by presence of more K+ ions inside the axon as compared to that of Na⁺ ions. So, addition of twice as much K⁺ to the extracellular fluid would cause depolarization of the membrane (V_m becomes more positive).