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Rank the following sulfides in order of decreasing solubility: MnS, CdS, SnS, Fe

ID: 874586 • Letter: R

Question

Rank the following sulfides in order of decreasing solubility: MnS, CdS, SnS, FeS. (Use the appropriate <, =, or > symbol to separate substances in the list. See theappendix.)

Substance Ksp at 25 oC Aluminum Al(OH)3 1.9 x 10-33 Barium Ba(OH)2 5.0 x 10-3 BaCO3 8.1 x 10-9 BaSO4 1.1 x 10-10 Ba3(PO4)2 3.4 x 10-23 Cadmium Cd(OH)2 2.5 x 10-14 CdCO3 5.2 x 10-12 CdS 8.0 x 10-27 Calcium Ca(OH)2 5.5 x 10-6 CaCO3 4.8 x 10-9 Ca3(PO4)2 1.0 x 10-26 CaF2 3.9 x 10-11 Chromium Cr(OH)3 6.3 x 10-31 Cobalt Co(OH)2 1.6 x 10-15 CoS 4.0 x 10-21 Copper Cu(OH)2 2.2 x 10-20 Cu2S 1.6 x 10-48 CuCO3 1.4 x 10-10 CuS 6.3 x 10-36 Iron Fe(OH)2 8.0 x 10-16 FeS 6.3 x 10-18 Fe(OH)3 2.5 x 10-39 FePO4 9.9 x 10-29 Lead Pb(OH)2 2.8 x 10-16 PbF2 3.7 x 10-8 PbCl2 1.7 x 10-5 PbBr2 6.3 x 10-6 PbI2 6.5 x 10-9 PbCrO4 1.8 x 10-14 PbSO4 1.7 x 10-8 PbS 8.4 x 10-28 Magnesium Mg(OH)2 1.8 x 10-11 Manganese Mn(OH)2 1.9 x 10-13 MnCO3 8.8 x 10-11 MnS 5.6 x 10-16 Nickel Ni(OH)2 1.6 x 10-14 Silver AgCl 1.8 x 10-10 AgBr 5.0 x 10-13 AgI 8.3 x 10-17 AgCN 1.2 x 10-16 Ag2S 6.3 x 10-50 Ag2CrO4 1.1 x 10-12 Ag3PO4 2.6 x 10-18 Tin Sn(OH)2 1.4 x 10-28 SnS 1.3 x 10-23 Zinc ZnCO3 1.0 x 10-10 Zn(OH)2 4.5 x 10-17 ZnS 1.1 x 10-21

Explanation / Answer

Ksp or solubility product constant is directly proportional to the number of ions in solution. That is higher the value of Ksp higher will be the solubility.

Therefore, the ranking of sulfides in order of decreasing solubility will be,

MnS > FeS > SnS > CdS

Note the Ksp value decreases in the above given order, and so is the solubility.