Assertio:`pK_a` value of phenol is 10.0 while that of ethanol is 15.9
Reason : Ethanol is stronger acid than phenol.

Options

A. if both assertioon and reason are true and reason is the corrct explanation of assertion.
B. If both assertion and reason are ture but reason is not the corrcet explanation of assertion.
C. If assertion is true but reason is false .
D. if both assertion and reason are false.

Explanation

To analyze the given statements regarding the acidity of phenol and ethanol, we will break down the assertion and reason step by step.

### Step 1: Understanding pKa Values
The pKa value is a measure of the strength of an acid; the lower the pKa value, the stronger the acid.

- **Assertion**: The pKa value of phenol is 10.0.
- **Reason**: The pKa value of ethanol is 15.9.

### Step 2: Comparing pKa Values
Since the pKa of phenol (10.0) is lower than that of ethanol (15.9), this indicates that phenol is a stronger acid than ethanol.

### Step 3: Evaluating the Reason
The reason states that ethanol is a stronger acid than phenol. However, based on the pKa values we just analyzed, this statement is incorrect. Ethanol has a higher pKa value, which means it is a weaker acid compared to phenol.

### Step 4: Conclusion
- The assertion is true: Phenol has a pKa of 10.0.
- The reason is false: Ethanol is not a stronger acid than phenol; it is weaker.

### Final Answer
Therefore, the correct conclusion is that the assertion is true, but the reason is false.