When zinc chloride (ZnCl2) reacts with NH3 solution, a white crystalline compound Zn(NH3)nCl2 is produced. A student used the procedure in this molecule to determine the mass percent of NH3 in Zn(NH3)nCl2. the student added 25.0 ml of 0.2500 M HCl solution to an aqueous solution containing 0.3145 g of Zn(NH3)nCl2. The excess HCl required 25.60 ml of 0.1000 M NaOH solution for complete titration. Caluclate the mass percent of NH3 in Zn(NH3)nCl2 based on the student's data