`pH` signifies:

Options

A. Puissance de hydrogen
B. `log [H^(+)]`
C. `-14 -pOH`
D. All the above

Explanation

To answer the question "pH signifies:", we will follow these steps:

### Step 1: Understand the Definition of pH
pH is a measure of the acidity or basicity of a solution. It is defined as the negative logarithm of the concentration of hydrogen ions (H⁺) in a solution.

### Step 2: Express pH Mathematically
The mathematical expression for pH is given by:
\[ \text{pH} = -\log[H^+] \]
where \([H^+]\) is the concentration of hydrogen ions in moles per liter.

### Step 3: Interpret the Meaning of pH
The term "pH" comes from the French "puissance d'hydrogène," which translates to "power of hydrogen." This indicates that pH is a logarithmic scale that reflects the power or concentration of hydrogen ions in a solution.

### Step 4: Analyze the Options
If the question provides multiple-choice options, we would evaluate each option based on the definition and mathematical expression of pH:
- If one of the options states that pH signifies the "power of hydrogen ions," that would be the correct answer.
- Other options that might suggest incorrect interpretations of pH, such as relating it directly to pOH or other unrelated concepts, would be incorrect.

### Step 5: Conclusion
Based on the understanding that pH signifies the power of hydrogen ions, we conclude that the correct answer is the option that states this definition.