A plot of these fractional concentrations against pH, for given K1 and K2, is known as a Bjerrum plot.
ɐ plˈɑːt ʌv ðiːz fɹˈækʃənəl kˌɑːnsəntɹˈeɪʃənz ɐɡˈɛnst pˈiː ˈeɪtʃ, fɔːɹ ɡˈɪvən kˈeɪ wˈʌn ænd kˈeɪ tˈuː, ɪz nˈoʊn æz ɐ bjˈɛɹəm plˈɑːt.