How do I know which salts are soluble in water? What generalization exists for chromate salts, i.e. salts of #CrO_4^(2-)#, and other salts?

1 Answer
Jun 22, 2017

Answer:

Well, chemistry is an experimental science.........which of course is determined by EXPERIMENT.

Explanation:

And it is a fact that chromate ion forms water-insoluble salts when treated with most heavy metals........, i.e. #PbCrO_4#, #BaCrO_4#, #Ag_2CrO_4#, #ZnCrO_4#, especially dications such as #Pb^(2+)# or #Ba^(2+)#.....

On the other hand, the salts of alkali metal are MOSTLY soluble.....

And in aqueous solution.....we can propose the following generalities....

#"All the salts of the alkali metals and ammonium are soluble."#

#"All nitrates, and perchlorates are soluble."#

#"All halides are soluble EXCEPT for"# # AgX, Hg_2X_2, PbX_2"#.

#"All sulfates are soluble EXCEPT for"# #PbSO_4, BaSO_4, HgSO_4#.

#"All carbonates and hydroxides are insoluble."#

#"All sulfides are insoluble."#

The given rules follow a hierarchy. Alkali metal and ammonium salts tend to be soluble in all circumstances. The one exception to this rule is #K^(+)""^(-)BPh_4# and #NH_4^(+)""^(-)BPh_4#, both of which are as soluble as bricks. #Na^+""^(-)BPh_4#, the which has some aqueous solubility, is sold as #"kalignost"#, i.e. #"potassium recognizer"#.............