A solution of silver nitrate (AgNO3 ) is added to a solution of sodium hydroxide (NaOH). In the precipitation reaction that occurs, which ions will be spectator ions?

Both ##Na^+## and ##NO_3^-## will be spectators.

We go back to simple solubility rules. All alkali metals salts are soluble. All nitrates are soluble. All halides are soluble (except for those of ##Ag^+## and ##Hg_2^(2+)##). All hydroxides are insoluble (except for previous).

So the net ionic equation representing the reaction is:

##Ag^+ + OH^(-) rarr AgOH(s)darr##

Silver hydroxide is not a well-characterized species. Its likely formulation is ##Ag_2O*(OH_2)##, a hydrous oxide of silver, but you don't need to know this in 6th form.