Analysis: (1) Sorbic acid and benzoic acid are ionized in water. Under acidic conditions, the equilibrium moves to the left, the number of acid molecules increases, and the anticorrosion effect is good. Under alkaline conditions, the equilibrium shifts to the right, the number of acid molecules decreases, and the anticorrosion effect is poor. (2) Potassium sorbate and sodium benzoate are completely ionized in aqueous solution: ch 3-ch = ch-ch = ch-cook ch 3-ch = ch-ch = chief operating officer -+k+C6H5coonaC6H5COO-+Na+, benzoic acid and sorbic acid are combined with H+ respectively to generate benzoic acid and sorbic acid, so that additives can be used. Therefore, potassium sorbate and sodium benzoate should be mixed with acid or acidic substances to achieve good anticorrosion effect. A: (1) Under acidic conditions, the ionization of sorbic acid and benzoic acid is inhibited, and there are many acid molecules, so the anticorrosion effect is good. Under alkaline conditions, it can promote the ionization of sorbic acid and benzoic acid, with few acid molecules and poor anticorrosion effect. Therefore, their corrosion resistance decreases with the increase of pH value. (2) Acids or acidic substances.