Determine the percent chloride composition of a sample in terms of magnesium chloride if a 0.6538 g sample was titrated with 50.0 mL of 0.1125 M silver nitrate solution and the excess silver ion was back titrated by 9.32 mL of 0.1005 M ammonium thiocyanate solution. Write the balanced chemical equation.

Atomic Masses: H – 1 C – 4 O – 16 N – 14 Na – 23 K – 39 Ag – 107 S – 32  Mg – 24

Ca – 40   Cl – 35.5     I – 126.9