Among the compounds provided, Hg2SO4, Cu2S, and Cu3(PO4)2 are insoluble in water, while Fe2(SO4)3, Mg(CrO4)2, and Ba(HCO3)2 are soluble. Insoluble compounds do not dissolve and remain as precipitates when mixed with water, while soluble compounds dissolve and form ions in water.
Among the compounds listed, the insoluble ones in water are Hg2SO4, Cu2S, and Cu3(PO4)2.
1. Hg2SO4 (Mercury(II) sulfate): This compound is insoluble in water. Sulfates are generally soluble, but mercury(II) sulfate is an exception. It forms a white precipitate when mixed with water.
2. Cu2S (Copper(I) sulfide): Copper(I) sulfide is insoluble in water. It is a black solid that does not dissociate into ions when mixed with water.
3. Cu3(PO4)2 (Copper(II) phosphate): Copper(II) phosphate is also insoluble in water. It forms a blue precipitate when added to water.
On the other hand, the compounds Fe2(SO4)3, Mg(CrO4)2, and Ba(HCO3)2 are soluble in water.
1. Fe2(SO4)3 (Iron(III) sulfate): Iron(III) sulfate is soluble in water and dissociates into ions.
2. Mg(CrO4)2 (Magnesium chromate): Magnesium chromate is soluble in water and dissociates into ions.
3. Ba(HCO3)2 (Barium bicarbonate): Barium bicarbonate is also soluble in water and dissociates into ions.