Is this a chemical burn?

Technically, it does sound like a chemical irritation, but a mild one. The area where the zit had been was just raw and sensitive (An open wound, pretty much.), no place for that strong stuff. If it's still burning, put some Aloe Vera or a drugstore gesic around it, avoid makeup on that area if you can, and if it's not fine in a couple of days, check with a dermatologist.