Explain that two half-cells can be connected by a salt bridge to create a galvanic cell, e.g. Mg, Zn, Fe and Cu and solutions of their ions.

A galvanic cell is constructed using an iron electrode in \(\text{Fe}^{2+}(aq)\) solution and a copper electrode in \(\text{Cu}^{2+}(aq)\) solution. The two half-cells are connected by a salt bridge containing \(\text{KNO}_3(aq)\). Which of the following best explains the role of the salt bridge in this galvanic cell?

A galvanic cell is constructed by connecting a zinc half-cell \(\text{Zn}^{2+}(aq)|\text{Zn}(s)\) and an iron half-cell \(\text{Fe}^{2+}(aq)|\text{Fe}(s)\) with a salt bridge containing potassium nitrate solution. Explain the primary function of the salt bridge in this galvanic cell.

A student constructs a galvanic cell using a copper electrode immersed in \(1.0 \text{ mol L}^{-1}\) copper(II) sulfate solution and an iron electrode immersed in \(1.0 \text{ mol L}^{-1}\) iron(II) sulfate solution. The two half-cells are connected by a salt bridge containing potassium nitrate solution. Explain the role of the salt bridge in allowing this galvanic cell to produce an electric current.