1. The electric potential outside a living cell is higher than inside the cell by 0.073 V. How much work is done by the electric force when a sodium ion moves from outside the cell membrane to inside the cell membrane. Assume the sodium ion is missing only one electron.

ΔW = 1.168 × 10 ⁻²⁰ Joule

Explanation:

Given:

Change in Electric potential Δ V=Vout - Vin=0.073 V

Charge on sodium ions q = 1.6 ×10 ⁻¹⁹ C (+ve because of Missing one electron)

Work done by the electric fore when a sodium ions moves from outside to inside the cell is the change in the Electric potential energy Uout -Uin = ΔU  

we have

ΔW =ΔU = q ΔV

ΔW = 1.6 ×10 ⁻¹⁹ C × 0.073 V

ΔW = 1.168 × 10 ⁻²⁰ Joule