Which of the following solutions will have the highest concentration of potassium ion (K^+)?

• A. 0.5 M KNO_3
• B. 0.5 M KHCO_3
• C. 0.5 M KCl
• D. 0.5 M K_2SO_4

Answer: (D)

Verified step by step guidance

1. Identify the source of potassium ions (K\^+) in each compound. Each compound dissociates in water to release K\^+ ions and its corresponding anions.
2. Write the dissociation equations for each compound: - KNO\_3 \rightarrow K\^+ + NO\_3\^- - KHCO\_3 \rightarrow K\^+ + HCO\_3\^- - KCl \rightarrow K\^+ + Cl\^- - K\_2SO\_4 \rightarrow 2K\^+ + SO\_4^{2\-}
3. Determine the number of potassium ions released per formula unit of each compound. For KNO\_3, KHCO\_3, and KCl, each formula unit releases 1 K\^+ ion. For K\_2SO\_4, each formula unit releases 2 K\^+ ions.
4. Calculate the concentration of K\^+ ions in each solution by multiplying the molarity of the compound by the number of K\^+ ions released per formula unit. For example, for K\_2SO\_4, the K\^+ concentration is \$0.5\,M \times 2 = 1.0\,M$.
5. Compare the K\^+ concentrations from each solution. The solution with the highest K\^+ concentration will be the one with the greatest product of molarity and number of K\^+ ions per formula unit.