CHEMISTRY COMMUNITY

J. 9. says: Identify the salt that is produced from the acid–base neutralization reaction between (a) potassium hydroxide and acetic acid,
CH 3 COOH; (b) ammonia and phosphoric acid; (c) calcium
hydroxide and bromous acid; (d) sodium hydroxide and hydrosulfuric acid, H2S (both H atoms react). Write the complete ionic
equation for each reaction.

I've noticed in the answer key, the ionic equation sometimes separates H+ from the acid on the reactant side and sometimes it leaves the acid as it is. Is there a reason why?

I don't have the textbook on me at the moment, but I'd assume it probably has something to do with the strength of the acid.

If an acid or base is strong, it will entirely ionize in solution. Thus, if the problem has a strong acid or base as a part of the equation, it must be written out in dissociated form (ex: HBr would be written as H+ and Br-). If the acid is weak (ex: CH3COOH, acetic acid), it does not entirely ionize in solution, so it must be written as unionized.