Question

A solution of Na,C,0, is added dropwise to a solution that is 0.0658 M in Cd2+ and 0.000500 M in Agt. The Ksp of CdC204 is 1.42e-08. The Ksp of Ag2C204 is 5.4e-12. (a) What concentration of C2042- is necessary to begin precipitation? (Neglect volume changes.) [C2042-] = M. (b) Which cation precipitates first? Cd2+ Agt (c) What is the concentration of C,042- when the second cation begins to precipitate? [C20-21 = C M .

Answer 1

Given data, Hep of dez 04 = 1.42X108 Ksp Of Agz C204 = 5:4x1512. 9, we know, Ksp = (6427) Ccg.oy) 11427108 - 6.0658 ) (200) con C204 = 4042X108 310658 162042 = 2.15X107M) Ksp = {2Ag+) (C204). S4x102= 2(0.000500) (C204) 514x1012 C2O4 = 0.00125 3204 = 5.4x100m) → Helle cd404 Precipitate flest sie co2+

c. we know, Ksp = (209) (C204) 5.4x1012 = 210.000500) (C204) (C204) = 0,001 (C204) - 514X1612 = 5:48109 m ezou.