4 AgNO3 (aq) + 4 NaOH (aq) → 4 NaNO3 (aq) + 4 Ag (s) + O2 (g) + 2 H2O (l)
This is an oxidation-reduction (redox) reaction:
4 AgI + 4 e- → 4 Ag0 (reduction)
2 O-II - 4 e- → 2 O0 (oxidation)
This is a precipitation reaction: Ag is the formed precipitate.
This is a gas evolution reaction, O2 is the formed gas.