Sodium hydroxide is added to a 0.1 M solution of phenylalanine.Phenylalanine is a diprotic acid with two pK_as,2.20 for the carboxylic acid group and 9.31 for the ammonium functional group.When the pH = 5.93,the principal species is____________________ and when the pH = 10.10,the principal species is____________________ .

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At pH 5.93, the principal species is HL because it is between the two pKa values, indicating the zwitterionic form. At pH 10.10, the principal species is L⁻ because the pH is above both pKa values, indicating deprotonation of both acidic groups.

Sodium Hydroxide Is Added to a 0