what mass of the AgCl precipitate should form?

Question

When silver nitrate is added to an aqueous solution of magnesium chloride, a precipitation reaction occurs that produces silver chloride and magnesium nitrate. When enough AgNO3 is added so that

40.3 g

of MgCl2 react, what mass of the AgCl precipitate should form?

Answer 1

AgNO₃(aq) + MgCl₂(aq) ==> 2AgCl(s) + Mg(NO₃)₂(aq)

40.3 g MgCl₂ x 1 mol MgCl₂/95.2 g = 0.423 moles MgCl₂ used with excess AgNO₃

mass of AgCl formed = 0.423 mol MgCl₂ x 2 mol AgCl/mol MgCl₂ x 143g/mol = 121 g AgCl