There is no single chemical formula for cereal because cereal is a food made from a mixture of different ingredients. The exact chemical composition varies depending on the specific type of cereal.

Here are some of the main ingredients found in cereal and their chemical formulas:

* Grains: The primary ingredient in most cereals is a grain like wheat (C6H10O5)n, rice (C6H10O5)n, or oats (C6H10O5)n.

* Sugar: Sugars like sucrose (C12H22O11) and glucose (C6H12O6) are often added for sweetness.

* Fat: Fats like vegetable oil (C57H104O6) and butter (C16H31COOH) are used for flavor and texture.

* Vitamins and minerals: Cereal is often fortified with vitamins and minerals, such as iron (Fe), calcium (Ca), and vitamin B12 (C63H88CoN14O14P).

Therefore, there's no single formula for cereal, but rather a combination of formulas for the individual components.