Question

What is a net ionic equation?

Answer 1

A net ionic equation includes only those species that participated in the reaction.

For example, the following equation represents a double replacement reaction, in which the calcium ions and phosphate ions switch partners, producing the precipitate calcium phosphate.

Molecular Equation:

`"2Na"_3"PO"_4("aq")` + `"3CaCl"_2("aq")` `rarr` `"6NaCl"("aq")` + `"Ca"_3("PO"_4)_2("s")`

The net ionic equation includes only the ions that reacted to produce the precipitate calcium phosphate. The other ions were in the solution, but did not react. They are called spectator ions.

Net Ionic Equation:

`"3Ca"^(2+)("aq")` + `"2PO"_4^(3+)("aq")` `rarr` `"Ca"_3("PO"_4)_2("s")`

The spectator ions are `"6Na"^+("aq")` and `"6Cl"^(-)("aq")`.

Another example:

video from: Noel Pauller