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 Acetoacetic Acid
Chemical formula: C4H6O3
Also known as: diacetic acid, 3-Oxobutanoic acid
Acetoacetic Acid is Acidic
At concentration of 1 mM, it has a pH of 3.4
At concentration of 10 mM, it has a pH of 2.83
At concentration of 100 mM, it has a pH of 2.3