-log10 [H+] where [H+] is the concentration of hydrogen ions The pH scale for acidity is defined by pH=-1 measured in moles per liter (M). (A) The pH of pure water is 7.0. Calculate the concentration of hydrogen ions in moles per liter (M). [H]= M (B) The pH of milk is 6.6. Calculate the concentration of hydrogen ions in moles per liter (M).