Explanation:
The given data is as follows.
pH of serine solution = 8.00
[tex]pK_{a}[/tex] of carboxylic group of serine = 2.21
[tex]pK_{a}[/tex] of amino group of serine = 9.15
Therefore, average net charge on serine will be as follows.
[tex]Q_{serine} = \sum Q^{-} + \sum Q^{+}[/tex]
= [tex]\frac{-1}{1 + 10^{-(pH - pK_{a} of carboxylic group}} + \frac{+1}{1 + 10^{pH - pK_{a} of amino group}}[/tex]
= [tex]\frac{-1}{1 + 10^{(8.00 - 2.21)}} + \frac{+1}{1 + 10^{(8.00 - 9.15)}}[/tex]
= [tex]\frac{-1}{1 + 10^{-5.79}} + \frac{+1}{10^{-11.5}}[/tex]
= (-0.999) + (0.934)
= 0.0660
Thus, we can conclude that average net charge on serine if it is in a solution that has a pH of 8.80 is 0.0660.
