Question

29. -10.1 points 0/4 Submissions Used A solution of Na3AsO4 is added dropwise to a solution that is 0.0361 M in B13+ and 0.000122 M in Cd2+. The Ksp of BiAsO4 is 4.43e-10. The Ksp of Cd3(AsO4)2 is 2.2e-33. (a) What concentration of AsO43- is necessary to begin precipitation? (Neglect volume changes.) [A5043-) = M. (b) Which cation precipitates first? O Bi3+ OCd2+ (c) What is the concentration of AsO43- when the second cation begins to precipitate? [A5043-) =

Answer 1

ksp (BiAs Ou) 4.43 1010 CBi+2J 0.0361 M BIASOY ksp Aso3 Bi 3 CBi3] [As o3] sp 43r 101(003 6 1) CAs o3] CAso43 227 x JoM sP[ed3(As Ou)2 2-2 x103 C ca2 0O00 122M Cd3(Aso42 3Ca*22 Aso43 Ksp + Ksp Cca2 CASO037 (o 000122) Asou3 2.2 x 1633 2 CAs Ou37 1u780 x 1025 LAsou3J3.84 x 105 M (a) to beign Preciptechion CAs O43] 3.8u x 163 Ars (b) fam egho cd3(As O)2 LAsO3 is Juss equircolfor so ca coilDreipitte Ast Ca2

(c) Bi is the Secord Cation uch will precipitek (BiJ 0 0361 M = 4.43x 101O ksp (BiAs Ou) Ksp As ou3 Bi 3 BiAsoy CBi3] [As o] sp (.0361) CAs o3] u. 43x 1D 8 (Aso3] Ar I 227 x O