Windex® is a commercial cleansing product used to clean windows. One of the active ingredients in Windex® is ammonia. The ammonia content of this product can be determined by converting first the ammonia to ammonium ions. Then, the ammonium ions are precipitated with chloroplatinic acid to form solid ammonium hexachloroplatinate, (NH4)2PtCl6. Lastly, the salt is decomposed by heat to give solid platinum according to the reaction given below.
(NH4)2PtCl6 → Pt(s) + 2NH3(g) + 2HCl(g) + 2Cl2(g) ?
When the reaction is terminated, the precipitate was filtered, washed and dried completely. What is the percent ammonia in Windex if a 2.000 g sample of Windex gave rise to 0.650 g of solid platinum?