Test the water quality of groundwater in Hsien-Hsi
I. Abstract
This experiment aimed at testing the water quality of groundwater in Hsien-Hsi, and contrasted with distilled water and tap water. It is found that tap water might contain chloride ion, whose pH is 7.3 with alkalescency; groundwater might contain chloride ion, sulfate ion, and carbonate ion, whose pH is 7.6 with alkalescency. This experiment was to test water quality of groundwater, and it did contain many different ions; therefore, we could speculate that the water quality might be polluted before. We have understood more about what we had learned and applied it to this experiment.
II. Research Motive & Purpose
1. Research Motive:
Before Toxic Egg incident, there was shocking water quality pollution problem; therefore, we’d like to aim at water source which might pollute ducks to do a simple test, and take advantage of it to understand the profile of water quality. This experiment is not only a simple test, and we hope that its result could arouse the conscious of environmental protection for water source among local residents in the future.
Before Toxic Egg incident, there was shocking water quality pollution problem; therefore, we’d like to aim at water source which might pollute ducks to do a simple test, and take advantage of it to understand the profile of water quality. This experiment is not only a simple test, and we hope that its result could arouse the conscious of environmental protection for water source among local residents in the future.
2. Research Purpose:
- Test if three kinds of water contains Cl- "chloride ion".
- Test if three kinds of water contains SO42- "sulfate ion".
- Test if three kinds of water contains CO32- "carbonate ion".
- Test if three kinds of water contains Br- "bromide ion" or I- "iodide ion".
- Test if three kinds of water contains Mn2+ "manganese(II)".
- Test if three kinds of water contains NH4+ "ammonium ion".
- Test the pH of three kinds of water.
III. Research Equipment & Drug
Equipment:
- 21 test tubes (18mm*180mm)
- 4 tube stands, a pack of labels
- 3 500mL-beakers
- 1 set pH meter
- red litmus paper
- 3 10mL-cylinders
- 8 droppers
Chemicals:
- Test water (500mL distilled water, 500mL tap water, 500mL groundwater)
- 100mL 0.1M- silver nitrate
- 100mL 1M-hydrochloric acid
- 100mL 1M-barium chloride
- 100mL 3M-nitric acid
- 1g sodium hydroxide
- 100mL 35% hydrogen peroxide
IV. Research Process & Ways
1. Experiment A- Water Quality of Distilled Water Test
Step1: Prepare distilled water and 6 test tubes, label A1-A6, and add 10ml distilled water into every test tube (as photo 1).
Step2: Add 5 drops of 3M-nitric acid into A1, mix it well, add 5 more drops of 0.1M- silver nitrate, and observe the solution change (as photo2).
Step3: Add 5 drops of 1M-hydrochloric acid into A2, mix it well, add 5 more drops of 1M-barium chloride, and observe the solution change.
Step4: Add 5 drops of 1M-barium chloride into A3, mix it well, and observe the solution change; if there is precipitation, add diluted nitric acid to observe the solution change.
Step5: Add 5 drops of 0.1M- silver nitrate into A4, mix it well, and observe the solution change.
Step6: Add 5 drops of 0.1M- silver nitrate into A5, mix it well, and add 35% hydrogen peroxide to observe the solution change.
Step7: Don’t add any reagent into A6 as a control group to observe changes of A1 to A5 with added reagent.
Step1: Prepare distilled water and 6 test tubes, label A1-A6, and add 10ml distilled water into every test tube (as photo 1).
Step2: Add 5 drops of 3M-nitric acid into A1, mix it well, add 5 more drops of 0.1M- silver nitrate, and observe the solution change (as photo2).
Step3: Add 5 drops of 1M-hydrochloric acid into A2, mix it well, add 5 more drops of 1M-barium chloride, and observe the solution change.
Step4: Add 5 drops of 1M-barium chloride into A3, mix it well, and observe the solution change; if there is precipitation, add diluted nitric acid to observe the solution change.
Step5: Add 5 drops of 0.1M- silver nitrate into A4, mix it well, and observe the solution change.
Step6: Add 5 drops of 0.1M- silver nitrate into A5, mix it well, and add 35% hydrogen peroxide to observe the solution change.
Step7: Don’t add any reagent into A6 as a control group to observe changes of A1 to A5 with added reagent.
2. Experiment B- Water Quality of Tap Water Test
Step1: Prepare tap water and 6 test tubes, label B1-B6, and add 10ml tap water into every test tube (as photo 3).
Step2: Add 5 drops of 3M-nitric acid into B1, mix it well, add 5 more drops of 0.1M-silver nitrate, and observe the solution change.
Step3: Add 5 drops of 1M-hydrochloric acid into B2, mix it well, add 5 more drops of 1M-barium chloride, and observe the solution change (as photo 4).
Step4: Add 5 drops of 1M-barium chloride into B3, mix it well, and observe the solution change; if there is precipitation, add 3M-nitric acid to observe the solution change.
Step5: Add 5 drops of 0.1M- silver nitrate into B4, mix it well, and observe the solution change.
Step6: Add 5 drops of 0.1M- silver nitrate into B5, mix it well, and add 35% hydrogen peroxide to observe the solution change.
Step7: Don’t add any reagent into B6 as a control group to observe changes of B1 to B5 with added reagent.
Step1: Prepare tap water and 6 test tubes, label B1-B6, and add 10ml tap water into every test tube (as photo 3).
Step2: Add 5 drops of 3M-nitric acid into B1, mix it well, add 5 more drops of 0.1M-silver nitrate, and observe the solution change.
Step3: Add 5 drops of 1M-hydrochloric acid into B2, mix it well, add 5 more drops of 1M-barium chloride, and observe the solution change (as photo 4).
Step4: Add 5 drops of 1M-barium chloride into B3, mix it well, and observe the solution change; if there is precipitation, add 3M-nitric acid to observe the solution change.
Step5: Add 5 drops of 0.1M- silver nitrate into B4, mix it well, and observe the solution change.
Step6: Add 5 drops of 0.1M- silver nitrate into B5, mix it well, and add 35% hydrogen peroxide to observe the solution change.
Step7: Don’t add any reagent into B6 as a control group to observe changes of B1 to B5 with added reagent.
3. Experiment C- Water Quality of Groundwater Test
Step1: Prepare groundwater and 6 test tubes, label C1-C6, and add 10ml groundwater into every test tube.
Step2: Add 5 drops of 3M-nitric acid into C1, mix it well, add 5 more drops of 0.1M-silver nitrate, and observe the solution change.
Step3: Add 5 drops of 1M-hydrochloric acid into C2, mix it well, add 5 more drops of 1M-barium chloride, and observe the solution change.
Step4: Add 5 drops of 1M-barium chloride into C3, mix it well, and observe the solution change; if there is precipitation, add 3M-nitric acid to observe the solution change(as photo 5).
Step5: Add 5 drops of 0.1M- silver nitrate into C4, mix it well, and observe the solution change.
Step6: Add 5 drops of 0.1M- silver nitrate into C5, mix it well, and add 35% hydrogen peroxide to observe the solution change.
Step7: Don’t add any reagent into C6 as a control group to observe changes of C1 to C5 with added reagent.
Step1: Prepare groundwater and 6 test tubes, label C1-C6, and add 10ml groundwater into every test tube.
Step2: Add 5 drops of 3M-nitric acid into C1, mix it well, add 5 more drops of 0.1M-silver nitrate, and observe the solution change.
Step3: Add 5 drops of 1M-hydrochloric acid into C2, mix it well, add 5 more drops of 1M-barium chloride, and observe the solution change.
Step4: Add 5 drops of 1M-barium chloride into C3, mix it well, and observe the solution change; if there is precipitation, add 3M-nitric acid to observe the solution change(as photo 5).
Step5: Add 5 drops of 0.1M- silver nitrate into C4, mix it well, and observe the solution change.
Step6: Add 5 drops of 0.1M- silver nitrate into C5, mix it well, and add 35% hydrogen peroxide to observe the solution change.
Step7: Don’t add any reagent into C6 as a control group to observe changes of C1 to C5 with added reagent.
4. Experiment D- Ammonia Test
Step1: Prepare 3 test tubes, add 10ml distilled water, tap water, and groundwater into test tubes separately, and label as follow: distilled water (A7), tap water (B7), and groundwater (C7) (as photo 6).
Step2: Add NaOH around 0.2g into A7, mix it well, put wet red litmus paper on the top of tube, and observe its change.
Step3: Add NaOH around 0.2g into B7, mix it well, put wet red litmus paper on the top of tube, and observe its change.
Step4: Add NaOH around 0.2g into C7, mix it well, put wet red litmus paper on the top of tube, and observe its change.
Step1: Prepare 3 test tubes, add 10ml distilled water, tap water, and groundwater into test tubes separately, and label as follow: distilled water (A7), tap water (B7), and groundwater (C7) (as photo 6).
Step2: Add NaOH around 0.2g into A7, mix it well, put wet red litmus paper on the top of tube, and observe its change.
Step3: Add NaOH around 0.2g into B7, mix it well, put wet red litmus paper on the top of tube, and observe its change.
Step4: Add NaOH around 0.2g into C7, mix it well, put wet red litmus paper on the top of tube, and observe its change.
5. Experiment E- pH Test
Step1: Prepare 3 beakers, add 200ml distilled water, tap water, and groundwater separately, and label them.
Step2: Use pH meter (calibrated) to test the pH, and keep records of experiment result.
Step1: Prepare 3 beakers, add 200ml distilled water, tap water, and groundwater separately, and label them.
Step2: Use pH meter (calibrated) to test the pH, and keep records of experiment result.
V. Research Result
1. Experiment A- Water Quality of Distilled Water Test Result (as photo 7)
- Add 5 drops of nitric acid into A1, mix with distilled water well, add 5 more drops of silver nitrate. No precipitation.
- Add 5 drops of hydrochloric acid into A2, mix with distilled water well, add 5 more drops of barium chloride. No precipitation.
- Add 5 drops of barium chloride into A3, and mix with distilled water well. No precipitation.
- Add 5 drops of silver nitrate into A4, and mix with distilled water well. No precipitation.
- Add 5 drops of silver nitrate into A5, mix with distilled water and hydrogen peroxide well. No precipitation. The solutions were still transparent and colorless.
2. Experiment B- Water Quality of Tap Water Test Result (as photo 8)
- Add 5 drops of nitric acid into B1, mix with tap water well, add 5 more drops of silver nitrate. White precipitation was produced.
- Add 5 drops of hydrochloric acid into B2, mix with tap water well, add 5 more drops of barium chloride. No precipitation.
- Add 5 drops of barium chloride into B3, and mix with tap water well. No precipitation.
- Add 5 drops of silver nitrate into B4, and mix with tap water well. White precipitation was produced but no light-yellow precipitation.
- Add 5 drops of silver nitrate into B5, and mix with tap water and hydrogen peroxide well. White precipitation was produced, but the solutions were still transparent and colorless after let it sit.
3. Experiment C- Water Quality of Groundwater Test Result (as photo 9)
- Add 5 drops of nitric acid into C1, mix with groundwater well, add 5 more drops of silver nitrate. White precipitation was produced.
- Add 5 drops of hydrochloric acid into C2, mix with groundwater well, add 5 more drops of barium chloride. White precipitation was produced.
- Add 5 drops of barium chloride into C3, and mix with groundwater well. White precipitation was produced and gas occurred when adding nitric acid.
- Add 5 drops of silver nitrate into C4, and mix with groundwater well. White precipitation was produced but no light-yellow precipitation.
- Add 5 drops of silver nitrate into C5, and mix with groundwater and hydrogen peroxide well. White precipitation was produced, but the solutions were still transparent and colorless after let it sit.
4. Experiment D- Ammonia Test Result (as photo 10)
After adding NaOH into A7, B7, and C7 test tubes, there was no color change of wet red litmus paper on the top of them.
After adding NaOH into A7, B7, and C7 test tubes, there was no color change of wet red litmus paper on the top of them.
5. Experiment E- pH Test Result
The pH for distilled water, tap water, and groundwater measured by pH meter were as below:
distilled water was 7.0 (as photo11); tap water was 7.3 (as photo 12); groundwater was7.6 (as photo 13).
The pH for distilled water, tap water, and groundwater measured by pH meter were as below:
distilled water was 7.0 (as photo11); tap water was 7.3 (as photo 12); groundwater was7.6 (as photo 13).
VI. Discussion
1. At step b in experiment A to C, silver ion and chloride ion in acid solution would produce silver chloride white precipitation easily, as following formula:
Ag+ + Cl- → AgCl↓
To prevent other nagative ion from interfering the test result, add saltpeter solution to acidulate three water ready for test in this experiment first and add silver nitrate to provide silver ion to test if distilled water, tap water, and groundwater contain chloride ion. B1 and C1 test tubes both produced white precipitation under this process, so we speculated that tap water and groundwater might contain chloride ion.
2. At step c in experiment A to C, barium ion and sulfate ion would produce barium sulfate white precipitation, as following formula:
Ba2+ + SO42- → BaSO4↓
Since barium ion and sulfate ion would react with other anion and produce white precipitation, and silver ion and chloride ion would also produce white precipitation, add hydrochloric solution to remove CO32- and Ag+ ions first and add barium chloride solution to provide barium ion to test if distilled water, tap water, and groundwater contain sulfate ion. C2 test tube produced white precipitation under this process, so we speculated that groundwater might contain sulfate ion.
3. At step d in experiment A to C, barium ion and sulfate ion might produce barium sulfate white precipitation, and barium ion with carbonate ion would produce barium carbonate precipitation, as following formula:
Ba2+ + CO32- → BaCO3↓
Only groundwater tube produced white precipitation after barium ion was added, since barium sulfate couldn’t dissolve in acid, but barium carbonate could dissolve in acid, as following formula:
BaCO3 +2 HNO3 → Ba(NO3)2 + H2O + CO2
C3 test tube produced gas after dilute nitrate was added, and part of white precipitation disappeared. Therefore, we speculated that groundwater might contain carbonate ion.
4. At step e in experiment A to C, add silver nitrate and mix it well to observe if light-yellow silver bromide and light-yellow silver iodide are produced, as following formula:
Ag+ + Br- → AgBr Ag+ + I- → AgI
Only B4 and C4 test tubes produced white precipitation but no light-yellow precipitation, so we speculated that tap water and groundwater might not contain iodide ion and bromide ion.
5. At step f in experiment A to C, add silver nitrate solution, after precipitation, add hydrogen peroxide. A5, B5, and C5 didn’t cause solution to be light-purple, and control group A6, B6 and C6 weren’t pink; therefore, we speculated that distilled water, tap water and groundwater might not contain manganese(II).
6. In experiment D, add NaOH into A7, B7 and C7 test tubes. If the solutions contain ammonium ion which would produce ammonia to make wet red litmus paper on the top of them become blue, but all three papers on them didn’t become blue; therefore, we
speculated that solutions didn’t contain ammonium ion.
7. In experiment E- pH test, distilled water (pH: 7.0) is neutral, tap water (pH: 7.3) and groundwater (pH: 7.6) are with alkalescency.
8. Result Table of Experiment A to E (as Table 1)
Ag+ + Cl- → AgCl↓
To prevent other nagative ion from interfering the test result, add saltpeter solution to acidulate three water ready for test in this experiment first and add silver nitrate to provide silver ion to test if distilled water, tap water, and groundwater contain chloride ion. B1 and C1 test tubes both produced white precipitation under this process, so we speculated that tap water and groundwater might contain chloride ion.
2. At step c in experiment A to C, barium ion and sulfate ion would produce barium sulfate white precipitation, as following formula:
Ba2+ + SO42- → BaSO4↓
Since barium ion and sulfate ion would react with other anion and produce white precipitation, and silver ion and chloride ion would also produce white precipitation, add hydrochloric solution to remove CO32- and Ag+ ions first and add barium chloride solution to provide barium ion to test if distilled water, tap water, and groundwater contain sulfate ion. C2 test tube produced white precipitation under this process, so we speculated that groundwater might contain sulfate ion.
3. At step d in experiment A to C, barium ion and sulfate ion might produce barium sulfate white precipitation, and barium ion with carbonate ion would produce barium carbonate precipitation, as following formula:
Ba2+ + CO32- → BaCO3↓
Only groundwater tube produced white precipitation after barium ion was added, since barium sulfate couldn’t dissolve in acid, but barium carbonate could dissolve in acid, as following formula:
BaCO3 +2 HNO3 → Ba(NO3)2 + H2O + CO2
C3 test tube produced gas after dilute nitrate was added, and part of white precipitation disappeared. Therefore, we speculated that groundwater might contain carbonate ion.
4. At step e in experiment A to C, add silver nitrate and mix it well to observe if light-yellow silver bromide and light-yellow silver iodide are produced, as following formula:
Ag+ + Br- → AgBr Ag+ + I- → AgI
Only B4 and C4 test tubes produced white precipitation but no light-yellow precipitation, so we speculated that tap water and groundwater might not contain iodide ion and bromide ion.
5. At step f in experiment A to C, add silver nitrate solution, after precipitation, add hydrogen peroxide. A5, B5, and C5 didn’t cause solution to be light-purple, and control group A6, B6 and C6 weren’t pink; therefore, we speculated that distilled water, tap water and groundwater might not contain manganese(II).
6. In experiment D, add NaOH into A7, B7 and C7 test tubes. If the solutions contain ammonium ion which would produce ammonia to make wet red litmus paper on the top of them become blue, but all three papers on them didn’t become blue; therefore, we
speculated that solutions didn’t contain ammonium ion.
7. In experiment E- pH test, distilled water (pH: 7.0) is neutral, tap water (pH: 7.3) and groundwater (pH: 7.6) are with alkalescency.
8. Result Table of Experiment A to E (as Table 1)
VII. Conclusion
- Distilled water might not contain chloride ion, sulfate ion, carbonate ion, bromide ion, iodide ion, manganese(II), and ammonium ion; pH is 7.0 and it is neutral.
- Tap water might contain chloride ion, but no sulfate ion, carbonate ion, bromide ion, iodide ion, manganese(II), and ammonium ion; pH is 7.3 and it is of alkalescency.
- Groundwater might contain chloride ion, sulfate ion, carbonate ion, but no bromide ion, iodide ion, manganese(II), and ammonium ion; pH is 7.6 and it is of alkalescency.
- Hsien-Hsi depended on groundwater to irrigate and breed fish in all ages, and residents used most water from it. Through this experiment, we found that groundwater contains many solutes which are unknown to people; if we have a chance, we’d like to ask relevant administrative units to promote the conscious of protection for water source and the safety of drinking water to protect local residents’ health.
- This experiment was to test water quality of groundwater, and it did contain many different ions; therefore, we could speculate that the water quality might be polluted before.
- We have practically applied what we had learned, such as solubility, acid-base reaction, and redox to this experiment, and known better about the knowledge and application from we had learned.
Reference (Traditional Chinese Website & Book)
Websites
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- 分析化學,陳昭雄主編,新文京開發出版股份有限公司,西元2006年9月25日。