Conditions: Which is more basic, As2O3 or As2O5? Solution: 1. Arsenic trioxide is an amphoteric oxide, and its aqueous solutions are weakly acidic. Thus, it dissolves readily in alkaline solutions to give arsenites. It is less soluble in acids, although it will dissolve in hydrochloric acid. With anhydrous HF and HCl, it gives AsF3 and the trichloride As2O3 + 6 HX → 2 AsX3 + 3 H2O (X = F, Cl)
2. As2O5 is dissolved in water to form arsenic acid, H3AsO4 – then As2O5 is more acidic,then As2O3 is more basic.