spectator ions in K equation

[Cylin Wang 2H]

Hello,

In the textbook example attached (Self-test 5G.3A), why is the Na+ excluded but the Ag+ included in the K constant equation?

Thank you & have a great weekend.

Stay hydrated everyone

[Giuliana_Ming_2D]

Hi! Na+ isn't used in the equation because the net ionic equation is used. This means that you would take every aqueous compound and split it into its ions since they dissociate in water. Once you split every aqueous compound you would cancel out any ion that didn't contribute to the non-aqueous compounds. Therefore, since Ag2O and H2O aren't aqueous as products, Ag+, and OH- are used, while NO3- and Na+ are not used, since they don't contribute to the non-aqueous compounds. The resulting net ionic equation would be 2Ag+(aq)+2OH-(aq) yields Ag2O(s)+H2O(l). Hope this helps!

[Jess Max 2F]

So just to clarify, Na+ and NO3- are classified as spectator ions in this equation? Because they are not part of non-aqueous compounds, and their product is aqueous, they are not included?
Thanks for the explanation!

[Cylin Wang 2H]

Hello

Thank you so much for clarifying

Na+ isn't used in the equation because the net ionic equation is used. This means that you would take every aqueous compound and split it into its ions since they dissociate in water. Once you split every aqueous compound you would cancel out any ion that didn't contribute to the non-aqueous compounds.

This really helps! Thank you for including this!