Example:A solution contains 0.10 molL-1 Cl and 0.0010molL-1 CrO2-.If the precipitating reagent AgNO3 is slowly added to the solution, which ion will precipitate first?Just before the second ion begins to precipitate,can the first ion precipitate completely?Example: A solution contains 0.10 mol.L-1 Cl－ and 0.0010mol.L-1 CrO4 2- . If the precipitating reagent AgNO3 is slowly added to the solution, which ion will precipitate first? Just before the second ion begins to precipitate, can the first ion precipitate completely?