Solution A has a pH of 4.0, and solution B has a pH of 6.0.
a. Which solution is more acidic?

Verified step by step guidance

1. Understand the concept of pH: The pH scale measures the acidity or basicity of a solution. A lower pH value indicates a more acidic solution, while a higher pH value indicates a less acidic (or more basic) solution. The scale typically ranges from 0 to 14.
2. Compare the pH values of the two solutions: Solution A has a pH of 4.0, and Solution B has a pH of 6.0. Since 4.0 is lower than 6.0, Solution A is more acidic than Solution B.
3. Explain the relationship between pH and hydrogen ion concentration: The pH is inversely related to the concentration of hydrogen ions ${[H+]}_{}$. A decrease in pH corresponds to an increase in hydrogen ion concentration, making the solution more acidic.
4. Highlight the logarithmic nature of the pH scale: The pH scale is logarithmic, meaning that each unit change in pH represents a tenfold change in hydrogen ion concentration. For example, a solution with a pH of 4.0 has 10 times more hydrogen ions than a solution with a pH of 5.0, and 100 times more hydrogen ions than a solution with a pH of 6.0.
5. Conclude the comparison: Based on the pH values and the relationship between pH and acidity, Solution A (pH 4.0) is more acidic than Solution B (pH 6.0).

Key Concepts

pH Scale

The pH scale measures the acidity or basicity of a solution, ranging from 0 to 14. A pH of 7 is considered neutral, while values below 7 indicate acidity and values above 7 indicate alkalinity. Each whole number change on the pH scale represents a tenfold change in hydrogen ion concentration, making it crucial for understanding the relative acidity of solutions.

Acidity

Acidity refers to the concentration of hydrogen ions (H+) in a solution. A higher concentration of H+ ions corresponds to a lower pH value, indicating a more acidic solution. Therefore, when comparing solutions, the one with the lower pH value is more acidic, which is essential for determining the relative acidity of solutions A and B.

Comparative Analysis

Comparative analysis involves evaluating two or more items to identify differences and similarities. In this context, it requires comparing the pH values of solutions A and B to determine which is more acidic. This method is fundamental in chemistry for making informed conclusions based on quantitative data.