The solution of Propranolol Hydrochloride (Mr = 295.8 g mol^-1) with a concentration of 1.80 g/L was prepared. Predict the theoretical pH of precipitation for this solution.

Measurement	Record
the pH of drug solution	3.9
The initial volume of NaOH (mL)	2.10
The final volume of NaOH (mL)	3.50
The total volume of NaOH used (mL)	1.40
pH at precipitation	8.4
The initial volume of HCl (mL)	2.70
The final volume of HCl (mL)	3.35
The total volume of HCl used (mL)	0.65
Appearance after adding water	Cloudy

Pka of propranolol = 9.50