Question 4 (35 points)
A 0.500 g sample contains only K_(2)SO_(4) (Molecular weight 174.25(g)/(m)ol ) and (NH_(4))_(2)SO_(4) (Molecular weight 132.13(g)/(m)ol ). This sample was dissolved in 50.0 mL of distilled water and treated with Ba(NO_(3))_(2)(aq) to precipitate all SO_(4)^(2-) as BaSO_(4) (Molecular weight 233.38(g)/(m)ol ). Weight of the rinsed and dried precipitate was 0.950 g .
a) Calculate the weight percent of K_(2)SO_(4) in the sample.
b) Calculate the concentration of K^(+)ions in ppm after sample was completely dissolved in 50.0 mL of distilled water.