The acidity and alkalinity of a compound is represented on a scale known as

Options

A. pH scale
B. Hess scale
C. Kelvin Scale
D. none of these

Explanation

**Step-by-Step Solution:**

1. **Understanding the Question**: The question asks about the scale that measures the acidity and alkalinity of a compound.

2. **Identifying the Scale**: The scale used to represent acidity and alkalinity is known as the pH scale.

3. **Explaining the pH Scale**:
- The pH scale ranges from 0 to 14.
- A pH of 7 is considered neutral, meaning the solution is neither acidic nor basic.
- Solutions with a pH less than 7 are classified as acidic. The lower the pH value, the more acidic the solution becomes due to an increase in hydrogen ion (H⁺) concentration.
- Conversely, solutions with a pH greater than 7 are classified as basic or alkaline. As the pH increases, the concentration of hydroxide ions (OH⁻) increases, leading to a stronger basicity.

4. **Conclusion**: Therefore, the correct answer to the question is that the acidity and alkalinity of a compound is represented on a scale known as the pH scale.

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