Which statement about pH is true?

Which statement about pH is true?

• A. The pH level determines water color.
• B. The pH value indicates how acidic or basic water is; pH below 7 is acidic.
• C. pH measures dissolved oxygen.
• D. pH reflects water temperature.

Answer: (B)

pH measures how acidic or basic water is on a 0–14 scale, with 7 being neutral at standard conditions. A pH below 7 indicates higher hydrogen ion activity, i.e., acidity. The pH value does not tell you water color, dissolved oxygen, or temperature; those are determined by other measurements. The scale is logarithmic, so each unit change represents a tenfold change in hydrogen ion concentration. In drinking water practice, pH affects corrosion control and disinfection, and a typical guideline range is about 6.5 to 8.5. This makes the statement that the pH value indicates acidity/basicity and that pH below 7 is acidic the correct description.

pH measures how acidic or basic water is on a 0–14 scale, with 7 being neutral at standard conditions. A pH below 7 indicates higher hydrogen ion activity, i.e., acidity. The pH value does not tell you water color, dissolved oxygen, or temperature; those are determined by other measurements. The scale is logarithmic, so each unit change represents a tenfold change in hydrogen ion concentration. In drinking water practice, pH affects corrosion control and disinfection, and a typical guideline range is about 6.5 to 8.5. This makes the statement that the pH value indicates acidity/basicity and that pH below 7 is acidic the correct description.