Question

When aqueous solutions of calcium nitrate and ammonium carbonate are combined, solid calcium carbonate and a solution of ammonium nitrate are formed?

. The net ionic equation for this reaction is:

Answer 1

`"Ca"_ ((aq))^(2+) + "CO"_ (3(aq))^(2-) -> "CaCO"_ (3(s)) darr`

Explanation:

The fact that this double replacement reaction produces solid calcium carbonate tells you which two ions will combine to form the solid and which two ions will be spectator ions.

As its name suggests, calcium carbonate contains calcium cations, `"Ca"^(2+)`, and carbonate anions, `"CO"_3^(2-)`.

The calcium cations come from the soluble calcium nitrate, `"Ca"("NO"_3)_2`, which implies that the nitrate anions, `"NO"_3^(-)`, will act as spectator ions.

Similarly, the carbonate anions come from the soluble ammonium carbonate, `("NH"_4)_2"CO"_3`, which implies that the ammonium cations, `"NH"_4^(+)`, will act as spectator ions.

You can thus say that you have

`"Ca"("NO"_3)_2 => {("Ca"^(2+) -> "part of the precipitate"), (2"NO"_3^(-) -> "spectator ions") :}`

`("NH"_4)_2"CO"_3 => {( 2"NH"_4^(+) -> "spectator ions"), ("CO"_3^(2-) -> "part of the precipitate") :}`

The net ionic equation, which does not include the spectator ions, will look like this

`"Ca"_ ((aq))^(2+) + "CO"_ (3(aq))^(2-) -> "CaCO"_ (3(s)) darr`

The complete ionic equation, which includes the spectator ions, will look like this

`"Ca"_ ((aq))^(2+) + 2"NO"_ (3(aq))^(-) + 2"NH"_ (4(aq))^(+) + "CO"_ (3(aq))^(2-) -> "CacO"_ (3(s)) darr + 2"NH"_ 4"CO"_ (3(aq))`