1. The problem statement, all variables and given/known data Write equations to illustrate whether P4O10(s) is an Arrhenius acid or a base. 2. Relevant equations P4O10(s) + H2O(l) will eventually have the H3O+ and a negative ion because it is a non-metallic oxide in water. 3. The attempt at a solution I can think of at least 10 different ways to come up with a H3O+ in the equation, but the answer has a specific answer which is, P4O10(s) + 6H2O → 4H3PO4(aq) I don't know why they have 6 H2O's. I also don't know why they only use one of the 4 H3PO4(aq) for this equation, H3PO4(aq) + H2O(l) → H3O+(aq) + H2PO4-(aq) . I can't find anywhere in the chapter that explains how I would know this.