A pH of 5 is how many times more acidic than a pH of 7?

A pH of 5 is how many times more acidic than a pH of 7?

• A. 10 times
• B. 50 times
• C. 100 times
• D. 1000 times

Answer: (C)

A pH of 5 is considered more acidic than a pH of 7. The pH scale is logarithmic, meaning that each whole number change on the scale represents a tenfold change in acidity or alkalinity. When comparing pH values, each decrease of one unit represents a tenfold increase in hydrogen ion concentration. Therefore, moving from a pH of 7 to a pH of 6 represents a tenfold increase in acidity, and moving from pH 6 to pH 5 represents another tenfold increase. Thus, when going from a pH of 7 to a pH of 5, you experience two full units of change, translating to 10 times 10, which equals 100 times more acidity. This understanding is crucial for interpreting how acidity levels change and is commonly used in fields such as horticulture, environmental science, and soil management where pH influences plant health and soil biology.

A pH of 5 is considered more acidic than a pH of 7. The pH scale is logarithmic, meaning that each whole number change on the scale represents a tenfold change in acidity or alkalinity.

When comparing pH values, each decrease of one unit represents a tenfold increase in hydrogen ion concentration. Therefore, moving from a pH of 7 to a pH of 6 represents a tenfold increase in acidity, and moving from pH 6 to pH 5 represents another tenfold increase. Thus, when going from a pH of 7 to a pH of 5, you experience two full units of change, translating to 10 times 10, which equals 100 times more acidity.

This understanding is crucial for interpreting how acidity levels change and is commonly used in fields such as horticulture, environmental science, and soil management where pH influences plant health and soil biology.