What is the common name of the reaction between o2 and the dianion of luminol?

This reaction is called as Chemiluminescence. A type of reaction in which light is produced due to chemical reaction. While in case of Phosphorescence and Fluorescence light is emitted due to absorption of photons.

When dianion of luminol is reacted with Oxygen, a unstable peroxide is formed, and elimination of Nitrogen gas takes place with the de-excitation of electrons from higher state to ground state and the energy is released in the form of Blue Light. 

Since there is the same amount of agn03 in both silver chloride and silver nitrate they produce the same amount of moles. therefore silver chloride produces the same amount of silver nitrate, so your answer is 15.0 moles of silver nitrate. i hope this !