`pH` of separate solution of four potassium salts, `KW,KX, KY` and `KZ` are `7.0, 9.0, 10.0`, and `10.5`, respectively. If each solution is `0.2M`, the strongest acid would be

Options

A. `HW`
B. `HX`
C. `HY`
D. `HZ`

Explanation

To determine the strongest acid among the potassium salts \( K_W, K_X, K_Y, \) and \( K_Z \) based on their pH values, we will follow these steps:

### Step 1: Understand the pH Values
The pH values of the solutions are given as:
- \( K_W: 7.0 \)
- \( K_X: 9.0 \)
- \( K_Y: 10.0 \)
- \( K_Z: 10.5 \)

### Step 2: Identify the Nature of the Solutions
Since the pH of \( K_W \) is 7.0, it indicates a neutral solution. The other salts \( K_X, K_Y, \) and \( K_Z \) have pH values greater than 7, indicating that they are basic solutions.

### Step 3: Relate pH to Acid Strength
The strength of an acid is inversely related to the pH of its solution. A lower pH indicates a higher concentration of hydrogen ions (\( H^+ \)), which corresponds to a stronger acid. Conversely, a higher pH indicates a lower concentration of hydrogen ions, which corresponds to a weaker acid.

### Step 4: Compare the pH Values
- \( K_W \) has the lowest pH of 7.0, which indicates it is neutral.
- \( K_X \) has a pH of 9.0, indicating it is weakly basic.
- \( K_Y \) has a pH of 10.0, indicating it is moderately basic.
- \( K_Z \) has the highest pH of 10.5, indicating it is the weakest among the basic solutions.

### Step 5: Determine the Strongest Acid
Since \( K_W \) has a pH of 7.0, it is neutral and does not produce any acidic ions. The other salts produce basic solutions. Therefore, the strongest acid corresponds to the salt that would produce the most acidic solution upon hydrolysis.

### Conclusion
The strongest acid among the given salts is associated with \( K_W \) because it has the lowest pH value, indicating it is the least basic and thus the strongest acid.

**Answer: The strongest acid would be \( HW \) (associated with \( K_W \)).**

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