Vitriolic Sphere

You point at a location within range, and a glowing, 1-foot-diameter ball of acid streaks there and explodes in a 20-foot-radius Sphere. Each creature in that area makes a Dexterity saving throw. On a failed save, a creature takes 10d4 Acid damage and another 5d4 Acid damage at the end of its next turn. On a successful save, a creature takes half the initial damage only.

Using a Higher-Level Spell Slot

The initial damage increases by 2d4 for each spell slot level above 4.