Answer:
K₃PO₄ and HBr
Explanation:
The premise of your question is incorrect.
A strong electrolyte is a substance that ionizes completely in solution.
For example, CaCO₃, is a strong electrolyte, even though it is insoluble.
Very little of it goes into solution, but every bit that does dissolve separates completely into ions.
In an ionic equation, we write it as CaCO₃(s) because it is insoluble.
An ionic equation shows soluble strong electrolytes as ions.
K₃PO₄ is a soluble strong electrolyte because salts of Group 1 metals are soluble.
HBr is a strong acid and a strong soluble electrolyte. In aqueous solution it dissociates completely into H⁺ and Br⁻.
Acetic acid is a soluble weak electrolyte. It is a weak acid, so only a few of its molecules dissociate into ions.