MAPP gas is a trade name for a mixture of gases. Its chemical formula isn't a single one, but rather a mix of the main components:

* Methylacetylene (Propyne): C₃H₄

* Propadiene (Allene): C₃H₄

* Propane: C₃H₈

* Other minor components

While MAPP gas is often described as a mixture of "methylacetylene-propadiene," it also contains propane and other trace components.

Therefore, there is no single chemical formula for MAPP gas.