I can't really follow what you are doing. Ammonia content is generally done by a back titration (due to volatility of ammonia) with bromocresol green indicator (offsets shift in pH at equivalence point). There is considerable uncertainty due to the volatility of HCl. Here is an example procedure with units in g NH3 / g solution (wt %):
Ex calculation:
To a 100 mL bottle was added 2.007 g of the ammonia solution, 3.156 g of concentrated HCl (36.5 - 38 wt %), 25 mL of water and 4 drops of bromocresol green indicator solution. The yellow solution was titrated until blue (16.80 mL) with 0.5998 M sodium hydroxide solution.
(0.5998 mol NaOH / 1 L) (0.0185 L) = 0.011096 mol NaOH used = 0.011096 mol HCl ---> (1 mol HCl / 1 mol NaOH)
added HCl = 3.156 g solution (0.37 g HCl / 1 g solution)(1 mol HCl / 36.5 g HCl) = 0.03199 mol
0.03199 mol HCl added - 0.011096 mol neutralized = 0.02089 mol consumed (1 mol NH3 / 1 mol HCl)*(17 g NH3 / 1 mol) / 2.007 g ammonia solution =
17.7 wt % NH3
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