Question

Which compound is insoluble in water?
(1) BaSO4 (3) KClO3
(2) CaCrO4 (4) Na2S

Answer 1

BaSO4
I hope this helps!

Answer 2

Answer:
`BaSO_4`

Explanation:

A precipitation reaction is a special type of double displacement reaction.

`BaSO_4` is an insoluble compound as it is does not dissolve in water, and thus formed as a soild or a precipitate.

The sulfate ion
`SO_4{2-}` form insoluble compounds when combined with
`Ba^(2+)`.

The chlorate ion
`ClO_3^-` form soluble compounds with all positive ions.

The chromate ion
`CrO_4^(2-)` form insoluble compounds with all ions but soluble with
`Ca^{2+`.

The sulfide ion
`S^(2-)` form insoluble compounds with all ions except when combined with
`Na^+` or
`NH_4^+`