Most chemical burns heal within 7 to 14 days.
It depends on the chemical that caused the burn and the best thing you can do for a chemical burn and what you should do is to immediately wash the chemical off your skin using soap and water.
Run the water over the chemical burn for 10 to 20 minutes or take a shower and wash off the chemical that burned your skin.
If the burn is really severe then get to the emergency room or urgent care to treat the chemical burn.
But small chemical burns do not require medical treatment other than home treatment unless the chemical burn gets more severe.
It's best to allow the chemical burn to breathe instead of covering it up.
If the chemical burn does not heal within a few weeks or it starts getting worse or you notice the chemical burn getting infected then seek medical attention.