2. Hexahistidine (HHHHHH, where H represents the amino acid histidine) is a very useful peptide for bioseparations. What would be the net charge on the peptide HHHHHH at pH 6.5? Assume the pKa values are 1.8 for the C-terminus of the peptide, 9.3 for the N-terminus, and 6.0 for the histidine side chains.