The pH of tap water can be measured with a Merck-colorimetric pH test.

• A. True
• B. False
• C. Not possible
• D. Not standard

Answer: (A)

Colorimetric pH testing relies on a chemical indicator that changes color in response to hydrogen ion activity. A Merck colorimetric pH test uses such indicators with a reference color chart, so you can estimate the tap water pH by comparing the sample color to the chart. This method is standard for routine water testing because it’s quick and practical, though it isn’t as precise as a calibrated pH meter. For reliable results, ensure you know the sample temperature, read the color under proper lighting, and be mindful of interference from highly colored or turbid water. Overall, using a Merck colorimetric pH test to measure tap water pH is a valid approach.