General Rules of Solubility:



 Any substance that can form 0.1 M or more concentrated is soluble.

Any substance that fails to reach 0.1 M is defined to be insoluble.

VERY FEW substances have their maximum solubility near to 0.1 M.

Almost every substance of any importance in chemistry is either much MORE soluble or much LESS soluble.

 
Formula
 Crystal
System
 Cell
Dimensions
 Solubility
a
 b
 c
 H2O
 H2SO4
PbSO4
 Orthorhombic
Dipyramidal 		8.48
 5.398 6.958 0.0425
 Less
soluble
a:b:c =1.5709:1:1.2889 Ksp=1.96E-08
BaSO4
 Orthorhombic
Dipyramidal 		8.878 5.45 7.152 0.0022
 Less
soluble
a:b:c =1.6289:1:1.3122 Ksp=8.89E-11
SrSO4
 Orthorhombic
Dipyramidal 		8.359 5.352 6.866 0.113
 Insoluble*
a:b:c =1.5618:1:1.2828 Ksp=3.78E-07
CaSO4
 Orthorhombic
Dipyramidal		 6.991
 6.996 6.238 3
 Insoluble*
a:b:c =0.9992:1:0.8916 Ksp=4.86E-04
MgSO4
 Monoclinic
 -
 -
 -
 260
 -
-
 Ksp=4.67
Na2SO4
 Orthorhombic
Dipyramidal 		9.75
 12.29 5.85 195
 -
a:b:c =0.7933:1:0.4759 Ksp=10.3
(NH4)2SO4
 Orthorhombic
Dipyramidal 		7.782
 5.993 10.636 706
 -
a:b:c =1.2985:1:1.7747 Ksp=611
*Note: if the Solubility Product (Ksp) is very small we can say that the salt is "Insoluble".

Graphs:

Cell Dimensions:



Solubility:





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Conclusions