Propane grills don't have a chemical formula. They are devices that use propane gas as a fuel source for cooking.

Here's a breakdown:

* Propane: The chemical formula for propane is C₃H₈. It's a colorless, odorless gas that is highly flammable.

* Propane grill: This is a cooking appliance that utilizes the combustion of propane gas to produce heat. It doesn't have a single chemical formula because it consists of various components like metal, ceramic, and other materials.

So, while propane itself has a chemical formula, the propane grill itself doesn't.