This little website shows you the pH of various acids, bases, food products, bodily fluids, cleaners, and more!
Here's a random substance:
pH of Hydrofluoric Acid
Chemical formula: HF
Also known as: Fluorhydric acid, Hydronium fluorid
Hydrofluoric Acid is Strongly Acidic
At concentration of 1 mM, it has a pH of 3.27
At concentration of 10 mM, it has a pH of 2.65
At concentration of 100 mM, it has a pH of 2.12