The products will be magnesium phosphate and potassium chloride. You then have to watch a solubility chart to see which one of these is not soluable. In this case it is magnesium phosphate.
1 of them would be baking or cooking because you can't redo that out of the same things. if that makes since.
Either covalent or ionic... they are nonmetals meaning that the are a component in both types of compounds
