How safe is your drinking water?

Mrs. Stevens

1/25/93

Acknowledgements

I would like to thank my parents for helping me obtain all of the water samples. I would also like to thank my science teacher for providing me with pH testing supplies.

Abstract

The problem that was being investigated was what is the affect of hydrogen ions on the quality of drinking water? Well water, Perrier bottled water and Dayton town water were the different types of water tested.

The procedures were first obtain 100 mL of each type of water. Distilled water was used as a control. Second, pout 20 mL of well water into the container. Hold the pH paper in the water until it changes colors. Compare the color of the pH paper with the chart that is provided and record the pH of the water. Thirdly, do the test on the well water two more times and find the average pH of the water. Fourthly, repeat the experiment using Perrier bottled water, Dayton town water and distilled water. Make sure each type of water is tested three times and the average is found for each type.

It was found that well water has the best pH because it is closest to a pH of seven which is neutral. The first trial tested at a pH of 7.5, the second trial tested with a pH of 7.2 and the third trial tested at a pH of 6.4, and the average pH level for the well water was 7.03. The bottled Perrier water tested the most acidic. The first trial tested at a pH of 6.5, the second trial tested at a pH of 6.7, the third trial test at a pH of 7.0 and the average pH level was 6.73. Dayton town water test to be the most alkaline out of the three water samples tested. The first trial tested a a pH of 7.9, the second trial tested at a pH of 7.8 , the third trial tested at a pH of 8.0 and the average pH level was 7.9. The distilled water was tested three times like the other water samples, each time testing at a pH of 7.0. The distilled water was used as a comparison for the other water samples.

  1. Problem

What is the affect of hydrogen ions on the quality of drinking water?

  1. Hypothesis

Well water will have the best pH quality of drinking water and Dayton town water will have the worst quality of drinking.

  1. Research

pH is a number used by chemists to tell how many hydrogen ions are in a certain solution. The letters pH stand for potential of hydrogen. The pH scale ranges from 0 to 14. A pH that is below 7 means the solution is acidic, if it is 7 it is pure. If the pH is above 7 the solution is alkaline. An example of a solution that has a pH of 7 is pure water.

A Danish biochemist Soren Sorensen invented the pH scale in 1909. A pH solution is defined as a negative logarithm, to the base of 10. The concentration is expressed in moles. A mole is one of the base units for the metric system.

pH is usually measured with an electronic pH meter or special dyes called acid – base indicators. The color of the indicator depends on the concentration of hydrogen ions. pH paper is another way to measure pH. The paper contains several indicators that change color when it is dipped into a solution. The paper will indicate the approximate pH of the solution.

  1. Materials
  2. 100 mL of well water
  3. 100 mL of bottles Perrier water
  4. 100 mL of Dayton water
  5. 100 mL of distilled water
  6. pH paper
  7. container
  8. paper
  9. pencil
  1. Procedures
  1. First collect the samples of drinking water.
  2. Pour 20 mL of well water into the container. Hold the pH paper in the water until the color changes. Compare the pH paper with the chart provided and record the corresponding pH number.
  3. Repeat with the well water two more times and then find the average pH.
  4. Do steps 2 and 3 again using Perrier, Dayton water, and distilled water.
  1. Results

Type of water / Trial 1 / Trial 2 / Trial 3 / Average
Well water / 7.5 / 7.2 / 6.4 / 7.03
Perrier water / 6.5 / 6.7 / 7.0 / 6.73
Dayton water / 7.9 / 7.8 / 8.0 / 7.9
Distilled water / 7.0 / 7.0 / 7.0 / 7.0

  1. Conclusion

The purpose of the experiment was to determine the quality of drinking water. I found out that Perrier water was the most acidic. Dayton water tested more on the alkaline side of the pH scale while well water tested close to neutral. Distilled water tested at 7.0 which is neutral. I reject my hypothesis because well water did have the best pH but Perrier water tested the worst. Perrier tested more acidic because it contains carbonic acid. Dayton water comes from Silver Lake which has a limestone base making the water more alkaline. If I were to do this experiment again, I would test more types of water that people commonly drinking. I think I would focus bottled water not city water systems.

Bibliography