How do you write a net ionic equation? Show an example please.

Question

Cameron Andrews · Accepted Answer

Assuming that you are also ignorant of how to write the entire ionic reaction, let's begin there.

Assuming that sodium phosphate and silver nitrate are reacting, the following is our unbalanced reaction:

#"AgNO"_3(aq) + "Na"_3"PO"_4(aq) -> "Ag"_3"PO"_4(s) + "NaNO"_3(aq)#

One way to counteract this is to first balance the sodium cations, which will then balance the nitrate polyatomic ions, which will subsequently balance the silver cations as well.

#3"AgNO"_3(aq) + "Na"_3"PO"_4(aq) -> "Ag"_3"PO"_4(s) + 3"NaNO"_3(aq)#

Everything aqueous is soluble in water, so the entire ionic reaction occurs when the soluble ions are separated out (don't forget to distribute the coefficients!).

#3"Ag"^(+)(aq) + 3"NO"_3^(-)(aq) + 3"Na"^(+)(aq) + "PO"_4^(3-)(aq) -> "Ag"_3"PO"_4(s) + 3"Na"^(+)(aq) + 3"NO"_3^(-)(aq)#

Observing the spectator ions on each side—that is, the ions shared by both sides—we can see that they don't do anything.

#3"Ag"^(+)(aq) + cancel(3"NO"_3^(-)(aq)) + cancel(3"Na"^(+)(aq)) + "PO"_4^(3-)(aq) -> "Ag"_3"PO"_4(s) + cancel(3"Na"^(+)(aq)) + cancel(3"NO"_3^(-)(aq))#

This cancellation of spectator ions results in the net ionic reaction:

#color(blue)(3"Ag"^(+)(aq) + "PO"_4^(3-)(aq) -> "Ag"_3"PO"_4(s))#

Essentially, it is merely a condensed form of the significant portion of the response.

Wyatt Adkins · Answer

undefined To write a net ionic equation, follow these steps:

1. Write the balanced molecular equation for the chemical reaction.
2. Write the complete ionic equation by breaking down all soluble ionic compounds into their respective ions.
3. Cancel out spectator ions (ions that appear on both sides of the equation).
4. Write the remaining ions as the net ionic equation.

Example:
Molecular equation: AgNO3(aq) + NaCl(aq) -> AgCl(s) + NaNO3(aq)

Complete ionic equation: Ag⁺(aq) + NO₃⁻(aq) + Na⁺(aq) + Cl⁻(aq) -> AgCl(s) + Na⁺(aq) + NO₃⁻(aq)

Net ionic equation: Ag⁺(aq) + Cl⁻(aq) -> AgCl(s)