Question

Write the formula of the compound in the grid when a precipitate forms and a (—) when no precipitate form?

Answer 1

(D)
`(NH_(4))_(2)S` (C)
`Ba(NO_(3))_(2)` (B)
`CuCl_(2)`

(A)
`K_(2)SO_(4)` _
`BaSO_(4)` _

(B)
`CuCl_(2)`
`Cu_(2)S_(2)` _

(C)
`Ba(NO_(3))_(2)` BaS

Explanation :

(1) Reaction for A + B

`K_(2)SO_(4)` +
`CuCl_(2)\rightarrow` 2KCl +
`CuSO_(4)`

In this reaction, there is no precipitate formed as the products are souble.

(2) Reaction for A + C

`K_(2)SO_(4)` +
`Ba(NO_(3))_(2)\rightarrow`
`BaSO_(4)` +
`KNO_(3)`

In this reaction,
`BaSO_(4)` is formed as precipitate as it do not dissolve.

(3) Reaction for A + D

`K_(2)SO_(4)` +
`(NH_(4))_(2)S\rightarrow`
`K_(2)S` +
`(NH_(4))_(2)SO_(4)`

In this reaction, there is no precipitate formed as the products are souble.

(4) Reaction for B + D

`2CuCl_(2)` +
`2(NH_(4))_(2)S\rightarrow`
`4NH_(4)Cl+Cu_(2)S_(2)`

In this reaction,
`Cu_(2)S_(2)` is formed as precipitate as it do not dissolve.

(5) Reaction for B + C

`CuCl_(2)` +
`Ba(NO_(3))_(2)\rightarrow`
`BaCl_(2)` +
`Cu(NO_(3))_(2)`

In this reaction, there is no precipitate formed as the products are souble.

(6) Reaction for C + D

`Ba(NO_(3))_(2)` +
`(NH_(4))_(2)S\rightarrow` BaS +
`2NH_(4)NO_(3)`

In this reaction, BaS is formed as precipitate as it do not dissolve.