Caustic Coat

A thin layer of blackish powder appears over a weapon you touch. If you hit a creature with this weapon during the allotted time, it takes an additional 2d6 acid damage, and 1d6 acid damage at the beginning of its next turn. Once you hit a creature with an affected weapon, or the time runs out, the spell's effects end on the weapon; a single weapon can only be affected by this spell once at a given time.

At Higher Levels. When you cast this spell using a spell slot of 2nd level or higher, the damage (both initial and later) increases by 1d6 for each slot level above 1st.