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 Nitrous Acid
Chemical formula: HNO2
Also known as: Hydroxidooxidonitrogen
Nitrous Acid is Strongly Acidic
At concentration of 1 mM, it has a pH of 3.28
At concentration of 10 mM, it has a pH of 2.67
At concentration of 100 mM, it has a pH of 2.13