Chemistry

=Chemistry=

Masatoki will be pouring NaCl (sodium chloride) into a sample of West lake water, and see how much precipitate it will make. The more precipitate it creates, the more lead the water contains because Cl will react with Pb (lead) and create a precipitate called lead chloride. I will compare the result with the result I get from tap water we have at school. I decided to use NaCl because then I can figure out how much lead is in water and only lead. If I used something else that would bond with lead and something else in water, then the precipitate I get would be the total sum of the two substances, which I wouldn't want.

I will also test for level of chlrine and phosphate in water.

petroleum distillants and hydrogen sulfide are two very hazardous substances that could potentially be in water. However, because test for these two substances need much more advanced equipments than what we could offer at school, I could not test for these.

Equipments: 3x 500ml beaker paper towel 50g NaCl (the actual thing) electric balance pipette

Tests done: Phosphate test - Ammonium molybdate and potassium antimonyl tartrate react in acid medium with orthophosphate to form a phsphomolybdate complex, which can be seen as a color of light blue. Orthophosphate is formed when phosphate reacts with water. The result of the experiment was negative. There were no phosphate in the sample of water taken.

Chloride ions test - For this test, two separate tests were carried out. Free chlorine test is a test in determining how much chloride ion is in water. When chloride ions react with contaminants, it becomes chloramines. Total chlorine test is a test in determining how much chloride ions and chloramines are present in the water. Total chlorine - Free chlorine = contaminants.

Because the only way to measure the volume of chloride ions and contaminants in the water was by looking at the color of the solution and the color codes that is shown right next to it. this means that the data collected was not very precise. Nevertheless, this is the result obtained: 0.5 ± 0.5 mg L^-1 - 0.2 ± 0.5 mg L^-1 = 0.3 ± 1.0 mg L^-1

Lead test NaCl was diluted with distilled water to create aqueous NaCl solution. This was then reacted with the lake water. If there were any lead present in the lake water, then precipitate, PbCl 2, would form within the solution. However, no precipitate formed, indicating that lead was not present in the lake water.


 * There were barely any or no chemicals in the lake water tested.
 * The lake where Lillie pads are growing - They could have absorbed chemicals from water into their stem.
 * Water is not necessarily clean because chemicals that were not tested may well be in the water.

Abstract: The chemist was to determine the contamination of Westlake by doing three tests; chloride ions, phosphate and lead. It was hypothesized that there was large volume of phosphate, lead and chloride ions in the water because many locals depend on the lake water and use it on a daily basis. Three tests were carried out to determine its quality. Despite small volume of chloride ions, there was no other chemical tested in the water; however, more tests should be carried out to better clarify the safety of water.

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