Which of the following ions is positively charged and is responsible for making a solution acidic?

• A. Cl^-
• B. H^+
• C. Na^+
• D. OH^-

Answer: (B)

Verified step by step guidance

1. Identify the charge on each ion given: Cl⁻ has a negative charge, H⁺ has a positive charge, Na⁺ has a positive charge, and OH⁻ has a negative charge.
2. Recall that an acidic solution is characterized by the presence of excess hydrogen ions (H⁺), which increase the solution's acidity.
3. Understand that ions like Cl⁻ and OH⁻ are negatively charged and do not contribute to acidity; OH⁻ actually makes a solution basic.
4. Recognize that Na⁺ is positively charged but is a spectator ion and does not affect the acidity of the solution.
5. Conclude that the ion responsible for making a solution acidic is H⁺, the positively charged hydrogen ion.