a. Suggest why aqueous silver nitrate is not used in a salt bridge when connecting a half-cell containing Zn and 1.00 mol dm^–3 ZnCl₂(aq) to another half-cell.

b. Write half-equations for the reactions taking place in the half-cells below. Write each equation as a reduction (electrons on the left-hand side of the equation).

i. Cr²⁺/Cr³⁺

ii. Br₂/2Br^–

iii. O₂ + H₂O/OH^– (make sure that you balance the equation)

iv. VO²⁺ + H₂O/VO₂⁺ + H⁺ (make sure that you balance the equation)