Suppose that each of the following pairs of redox couples is combined to form a galvanic cell that generates a current under standard conditions. Identify the oxidizing agent and the reducing agent, write a cell diagram, and calculate the standard cell potential from the standard potentials of the electrodes.

(a) Co²⁺/Co and Ti³⁺/Ti²⁺;

(b) La³⁺/La and U³⁺/U;

(c) H⁺/H₂ and Fe³⁺/Fe²⁺;

(d) O₃/O₂,OH^– and Ag₊/Ag.