Strontium and barium
Strontium and barium resemble calcium very much. These also are reactive metals, which react with water, forming hydrogen and the metal hydroxide. They are more reactive than calcium and hence, they keep even worse than calcium. The metals are not interesting for the home chemist.
These metals only exist in the +2 oxidation state in their compounds. The Sr2+ and Ba2+ ions are colorless. Compounds of strontium and barium are white or colorless/transparent, as long as the anion is colorless.
The solution chemistry of strontium and barium also resembles that of calcium very much. The solubility of sulfates and carbonates decreases gradually when going from Ca to Ba, the solubility of hydroxides increases gradually when going from Ca to Ba.
From pottery and ceramics suppliers both strontium carbonate and barium carbonate are available. These can be used as the basis for preparing other strontium salts and barium salts. The carbonates from pottery suppliers usually contain a small amount of sulfide as an impurity.
The use of strontium salts and barium salts is limited in aqueous chemistry. They have no extensive redox chemistry and only a limited coordination chemistry. They, however, form precipitates with quite some anions. Soluble salts of strontium or barium can be used for detecting sulfate. Especially barium sulfate is highly insoluble, even in strongly acidic media. Barium sulfite is soluble in acidic media, allowing the purity of sulfite and metabisulfite to be tested. If a solution of e.g. sodium sulfite, acidified with hydrochloric acid, does not form a cloudy liquid with a clear solution of a barium salt, then one can conclude that the sulfite is not (yet) oxidized to sulfate to any considerable extent.
In dry-chemistry experiments, barium carbonate and strontium carbonate can be interesting. Barium salts give a grey/green color of the flame and strontium salts give a bright red color of the flame. When the carbonates from pottery and ceramics supplies are used, then it is wise not to store premixed powders, because of the sulfide impurity. This may strongly sensitize mixtures, especially with chlorates.
Barium compounds
are quite toxic. Be careful not to get in contact with barium chemicals.
Especially when fine powders are used, be sure not to inhale any
barium-containing dust!
Strontium and its compounds are not particularly toxic.