Ag+/Ag，标准电极电势φθ = 0.8VCu2+/Cu,标准电极电势φθ = 0.34V电动势E=φθAg+/Ag-φθCu2+/Cu >02Ag+ +Cu = Cu2+ +2AgCu失去电子做负极，Ag+得到电子做正极
