Question

How would you compare the relative solubilities of \[BaCr{{O}_{4}}\]and \[BaC{{r}_{2}}{{O}_{7}}\]?

Answer 1

Hint: The solubility is a property which has been defined as the ability of the solid, liquid or the gaseous substances which tend to dissolve in the solvent so that the formation of the solution takes place. The solubility of the substance generally depends upon the solvent which has been used. It also depends upon the temperature and the pressure present at the time of the dissolution in the solvent.

Complete step-by-step answer: The \[BaCr{{O}_{4}}\]is known as the barium chromate and \[BaC{{r}_{2}}{{O}_{7}}\]is known as barium dichromate. The dichromate salts are generally said to be more soluble than that of the corresponding salts of the chromate. This is so because the salts of the dichromate are larger in size than the chromate salts and so the density of charge in dichromate salt will be less therefore they will be less effectively solvated in the aqueous medium and the ionic bond formed between the cation and the dianion would be weaker. So the entropy as well as the enthalpy suggests to us that the barium dichromate is more soluble than the chromate salt or the barium chromate. So the barium dichromate is more soluble in comparison to the barium dichromate.

Note: The oxidation state of the chromium in the barium dichromate is +6 as the charge of the dichromate is 2-. The barium dichromate is known as the mild oxidising agent. It helps in the selective conversion of the primary as well as the secondary alcohols into the corresponding aldehydes and the ketones.