In order to get AgCl precipitate first,then... When AgCl and AgI precipitate at the same time: G(Ag")c=c2(Ag)(AgCD(AgD c(CI) c) K(AgCl c(CI)(Ag .c）) 1.8×1010 83x107c)=2.2x10fc） We know that AgCl will precipitate first when c(Cl) >2.2x106cF)- - + + < 1 Cl 2 I c (Ag ) ＝ c (Ag ) (I ) (AgI) (Cl ) (AgCl) θ sp θ sp - - < c K c K ＝ (I ) 8.3 1 0 1.8 1 0 (I ) (AgI) (AgCl) (Cl ) 17 10 θ sp θ sp - - - - -   > c = c K K c 2.2 10 (I ) 6 - =  c ＝ When AgCl and AgI precipitate at the same time： In order to get AgCl precipitate first, then… We know that AgCl will precipitate first when c(Cl- ) >2.2 x 106c(I- )