Ammonium cerium(IV) sulfate, with the chemical formula (NH4)4Ce(SO4)4, is a chemical compound composed of ammonium ions (NH4+), cerium ions in the +4 oxidation state (Ce4+), and sulfate ions (SO4^2-). It is a yellow or orange crystalline solid.

Ammonium cerium(IV) sulfate is an important chemical in certain chemical reactions and applications, particularly in redox reactions and analytical chemistry. Some key properties and uses include:

1. Oxidizing Agent: Ammonium cerium(IV) sulfate is a powerful oxidizing agent. It can transfer oxygen atoms to other substances during chemical reactions, facilitating oxidation processes.
2. Redox Reactions: It is used in various redox reactions, where it acts as an oxidizing agent, causing other substances to undergo reduction.
3. Titration Agent: In analytical chemistry, ammonium cerium(IV) sulfate is used as a titration agent to determine the concentration of certain substances in a solution.
4. Cerium Ion Source: It is utilized as a source of cerium ions in certain chemical reactions and processes.

Ammonium cerium(IV) sulfate is a hazardous chemical and should be handled with care in a laboratory setting. It is considered toxic and can cause skin and eye irritation upon contact. Proper safety precautions, such as the use of personal protective equipment and appropriate ventilation, should be followed when working with this compound.

Due to its reactivity and usefulness as an oxidizing agent, ammonium cerium(IV) sulfate is an important tool in various chemical reactions, especially those involving redox processes and analytical determinations. However, its use requires a good understanding of its properties and careful handling to ensure safety and successful outcomes in laboratory applications.