Final answer:
Potassium phosphate (K3PO4) would contain the highest concentration of potassium ions.
Step-by-step explanation:
Out of the given options, potassium phosphate (K3PO4) would contain the highest concentration of potassium ions (K+).
This is because potassium phosphate dissociates into three potassium ions and one phosphate ion when dissolved in solution, while the other options only produce one potassium ion. Therefore, potassium phosphate would have the highest concentration of potassium ions.
It's important to note that Molarity (M) measures the concentration of a solute in a solution, and a 0.300 M solution means there are 0.300 moles of solute per liter of solution.