Textbook J.9

[Kaleigh Olla 1L]

Question J.9 in the textbook says "Identify the salt that is produced from the acid–base neutralization reaction between (a) potassium hydroxide and acetic acid,
(b) ammonia and phosphoric acid; (c) calcium hydroxide and bromous acid; (d) sodium hydroxide and hydrosulfuric acid,
(both atoms react). Write the complete ionic equation for each reaction."

could someone explain how to get the products for (b) and (c)? It doesn't seem obvious to me that NH4+ and PO43- are left as ions and Br binds to O2.

[Ethan Famas 1H]

With these problems, it could be a little difficult to visualize how the reaction progresses. This is my thought process:

b) We have ammonia (NH₃, which is a base) and phosphoric acid (H₃PO₄). Ammonia is a molecule and so it doesn't dissociate into ions the way H₃PO₄, an Arrhenius acid, does. H₃PO₄ dissociates into 3H+ and PO₄^3-. Because NH₃ is a base, it can accept H+ from the H₃PO₄, creating ammonium ion NH₄+. Therefore, our product salt would be the combination of the NH₄+ and the PO₄^3-. (We would need three of the NH₄+ to neutralize the 3- charge of the PO₄^3-, so that's why the salt is (NH₄)₃PO₄.)

c) We have calcium hydroxide Ca(OH)₂, and bromous acid (HBrO₂). Both can dissociate into ions. The -OH from Ca(OH)₂ and the H+ from HBrO₂ form water, and the ions Ca²⁺ and BrO₂^- form the salt, Ca(BrO₂)₂. (We need two of the BrO₂^- to neutralize the Ca²⁺.)