The pH value of a 10 M solution of HCl is

Options

A. less than 0
B. equal to 0
C. equal to 1
D. equal to 2

Explanation

To find the pH value of a 10 M solution of HCl, we can follow these steps:

### Step 1: Understand the dissociation of HCl
HCl is a strong acid that completely dissociates in water. The dissociation can be represented as:
\[ \text{HCl} \rightarrow \text{H}^+ + \text{Cl}^- \]

### Step 2: Determine the concentration of H⁺ ions
Since the concentration of HCl is given as 10 M, and it completely dissociates, the concentration of H⁺ ions will also be 10 M:
\[ [\text{H}^+] = 10 \, \text{M} \]

### Step 3: Use the pH formula
The pH of a solution is calculated using the formula:
\[ \text{pH} = -\log[\text{H}^+] \]

### Step 4: Substitute the concentration of H⁺ ions into the pH formula
Now we can substitute the concentration of H⁺ ions into the formula:
\[ \text{pH} = -\log(10) \]

### Step 5: Calculate the pH
Using the logarithmic property:
\[ \log(10) = 1 \]
Thus,
\[ \text{pH} = -1 \]

### Conclusion
The pH of a 10 M solution of HCl is -1, which means it is less than 0.

### Final Answer
The pH value of a 10 M solution of HCl is less than 0.

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