What is the concentration of hydrogen ions in a solution of pH = 4.0? Chemistry Acids and Bases pH 1 Answer Professor Sam Jun 17, 2017 #"concentration of H"^+ = "0.0001M"# Explanation: #"pH" = -log("concentration of H"^+)# #or, 10^-"pH" = "concentration of H"^+# From the given info #"pH"# = 4 #therefore 10^-4 = 0.0001# #"concentration of H"^+ = "0.0001M"# Answer link Related questions How do you determine pH from pKa? How do pH values of acids and bases differ? How do you calculate something on a pH scale? How do you calculate pH diprotic acid? How do you calculate pH from acid dissociation constant? How do you calculate pH of acid and base solution? Why is the pH scale 0-14? Is pH a measure of the hydrogen ion concentration? How does solubility affect pH? How does pH relate to pKa in a titration? See all questions in pH Impact of this question 17581 views around the world You can reuse this answer Creative Commons License