Acid is one of the most sought after components in Fallout 76. It is heavily used at the Chemistry workbench to craft items like Gunpowder or to smeltore, and trust me, you need a LOT.
Besides finding Acid straight up in certain places, the key items you can deconstruct to find Acid are:
Abraxo Cleaner
Bags of Fertilizer
Bloatfly Glands
Coolant
Makeshift Batteries
As you keep an eye on finding those kinds of items, there are ALSO enemies that carry decent amounts of Acid, so you’ll need areas to find them.
The Snallygaster is hands down the best way to Farm Acid in Fallout 76. They have several spawn locations (sometimes you have a 50/50 chance of them spawning). Here are the locations where you can find Snallygasters Spawning:
Toxic Larry’s Meat n’ Go
Pylon V-13
Flooded Trainyard
By jumping between these three locations, with each Snallygaster carrying approximately 5 Acid PER kill, you’ll be getting an easy 20-50 Acid doing this run.