Cerium(IV) sulfate

Cerium(IV) sulfate, also known as ceric sulfate, is an inorganic compound with the chemical formula Ce(SO₄)₂. It is a powerful oxidizing agent, finding use in various analytical chemistry applications and organic synthesis. It typically exists as a hydrate, represented as Ce(SO₄)₂·xH₂O, where x is the number of water molecules. The number of water molecules can vary.

Properties:

Cerium(IV) sulfate is typically a yellow or orange-colored solid. Its color arises from charge-transfer transitions. It is soluble in water, especially in acidic solutions. The solutions are intensely yellow. The oxidizing power of ceric sulfate is dependent on the acidity of the solution, with stronger oxidation occurring in more acidic environments. The standard reduction potential for the Ce⁴⁺/Ce³⁺ couple is around +1.7 V in 1 M H₂SO₄, making it a stronger oxidizing agent than permanganate (MnO₄^-). In neutral or basic solutions, cerium(IV) tends to hydrolyze, forming insoluble cerium(IV) hydroxide.

Synthesis:

Cerium(IV) sulfate can be prepared by oxidizing cerium(III) compounds with strong oxidizing agents like ozone, hydrogen peroxide, or electrolytically. A common method involves dissolving cerium(III) oxide or cerium(III) carbonate in sulfuric acid, followed by oxidation.

Uses:

• Analytical Chemistry: It is a widely used volumetric reagent in redox titrations. It can be used to determine the concentration of various reducing agents, such as ferrous ions, oxalate ions, and arsenic(III) compounds.
• Organic Synthesis: It serves as an oxidizing agent in various organic reactions, including the oxidation of alcohols to aldehydes or ketones, and the cleavage of certain protecting groups.
• Catalysis: Cerium(IV) sulfate can act as a catalyst in certain reactions.
• Photography: Formerly used as a component in certain photographic processes.

Safety:

Cerium(IV) sulfate is a strong oxidizing agent and should be handled with care. It can cause irritation to the skin, eyes, and respiratory tract. Appropriate personal protective equipment, such as gloves, eye protection, and a lab coat, should be worn when handling this compound. Ingestion can cause gastrointestinal distress. While cerium compounds are generally considered to have low toxicity compared to some other heavy metals, prolonged or excessive exposure should be avoided. Refer to the Material Safety Data Sheet (MSDS) for detailed safety information.