Based on these descriptions, write a balanced equation and the corresponding expression for each reversible reaction.

(a) Carbonyl fluoride, COF₂(g), decomposes into gaseous carbon dioxide and gaseous carbon tetrafluoride.

(b) Copper metal displaces silver(I) ion from aqueous solution, producing silver metal and an aqueous solution of copper(II) ion.

(c) Peroxodisulfate ion, S₂O₈^2-, oxidizes iron(II) ion to iron(III) ion in aqueous solution and is itself reduced to sulfate ion.