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 Formic Acid
Chemical formula: CH2O2
Also known as: methanoic acid, Carbonous acid, Formylic acid, Hydrogen carboxylic acid, Metacarbonoic acid, Oxocarbinic acid, Oxomethanol
Formic Acid is Strongly Acidic
At concentration of 1 mM, it has a pH of 3.47
At concentration of 10 mM, it has a pH of 2.91
At concentration of 100 mM, it has a pH of 2.38