# What does the formation of a precipitate indicate?

Feb 9, 2017

Well, it indicates that a chemical reaction has taken place.

#### Explanation:

And we can illustrate the formation of a precipitate by a stoichiometrically balanced equation:

$A g N {O}_{3} \left(a q\right) + N a C l \left(a q\right) \rightarrow A g C l \left(s\right) \downarrow + N a N {O}_{3} \left(a q\right)$

And because the nitrate and sodium ions are along for the ride, we could write a net ionic equation:

$A {g}^{+} + C {l}^{-} \rightarrow A g C l \left(s\right) \downarrow$

Bonds are broken, and bonds are formed in a new substance, and thus chemical change has manifestly occurred.