Question

Unlabeled test tube contains solid ${AlCl}_3$ ${6H}_{2}O$ in one, ${Ba\left(OH\right)}_2$ ${8H}_{2}O$ in another, and ${MgSO}_4$ ${7H}_{2}O$ in the other. How could you find what is in each test tube using chemical tests that involve only these compounds plus water?

Answer 1

Label them yourself as (A) for ${AlCl}_3$ ${6H}_{2}O$ (B) for ${Ba\left(OH\right)}_2$ ${8H}_{2}O$ and (C) for ${MgSO}_4$ $H_{2}O$
[(A), (B) and (C) are unknown till confirmed]; mix (B) and (C) white ppt confirms that one of them is ${Ba\left(OH\right)}_2$ and the other ${MgSO}_4$. Add (B) and (C) each to (A) (which is certainly ${AlCl}_3$ ${6H}_{2}O$) of white ppt of [of ${Al\left(OH\right)}_3$] then that compound is (B).