# Will sodium fluoride and calcium nitrate react to produce a precipitate?

Apr 25, 2017

There is a precipitate, which is calcium fluoride, $\left(\text{CaF"_2}\right)$.

#### Explanation:

Balanced Equation

"2NaF(aq) + Ca(NO"_3)_2("aq")$\rightarrow$$\text{CaF"_2("s") + "2NaNO"_3("aq")}$

As you can see, a precipitate (solid) does form, and it is calcium fluoride $\left(\text{CaF"_2}\right)$.

This is an example of of a double replacement (double displacement or metathesis) reaction. Evidence of a double replacement reaction include a precipitate, or an insoluble gas must bubble out of solution, or water must be a product (neutralization reaction). The generic equation that represents a double replacement reaction is:

$\text{AX + BY}$$\rightarrow$$\text{AY + BX}$

where $\text{A and B}$ are cations, and $\text{X and Y}$ are anions.

There are solubility rules that can help you determine whether a precipitate will form, and what it is. As you can see, fluoride and calcium ions form a solid, as designated by an "s".