There is no single chemical formula for "amide" because it is a functional group, not a specific compound.

The general formula for an amide functional group is:

R-CO-NH₂

Where:

* R represents any alkyl or aryl group (a chain of carbon and hydrogen atoms, or a ring structure containing carbon and hydrogen).

* CO represents a carbonyl group (a carbon double-bonded to an oxygen atom).

* NH₂ represents an amino group (a nitrogen atom bonded to two hydrogen atoms).

Examples of specific amides include:

* Methanamide (formamide): HCONH₂

* Ethanamide (acetamide): CH₃CONH₂

* Benzamide: C₆H₅CONH₂

Important Note: Amides are a large and diverse family of compounds, with varying structures and properties. Their specific formula depends on the nature of the R group attached to the carbonyl group.