Water testing Lab Report

Abstract:

             In the water testing lab my lab group was testing for three different types of ions in five different types of liquid we were given. The first ion we were examining for was Calcium Ion (Ca²⁺). We had five different types of liquids that we test for Calcium Ions; distilled water, the control, ocean water, tap water, and the reference. The reference is the sample we compared all the other liquids, to conclude that there is a presence of Calcium Ions in the liquid. For each of those liquids we added three drops of Sodium carbonate  and we compared the distilled water, control, ocean water, and tap, with the Sodium Carbonate, to the reference. If any of the liquids resembled the reference then we knew it had Calcium Ions in it. After adding the Sodium Carbonate to the different liquids, we noticed that the reference formed small particles. That meant that any of the liquids that formed small particles after adding the Sodium Carbonate had calcium ions in the liquid. The distilled water had no reaction, which meant there were no Calcium ions in it. For the control solid particles formed, also known as precipitates, which meant that there was a presence of Calcium Ions in the control. In the ocean water, after adding Sodium Carbonate, the liquid also formed precipitates, proving that there is a presence of Calcium ions in the ocean water. Concluding that the distilled water, and tap water nothing formed meaning there wasn't a presence of Calcium Ions in it. For the ocean water and the control, there was a presence of Calcium Ions.

          The second Ion we where testing for was Iron(III) Ion (Fe³⁺). We used the exact same liquids as before, but added a different chemical into those liquids. The chemical we added to the liquids was Potassium Thiocyante. When we added Potassium Thiocyante to the reference the liquid turned into a dark red color and had precipitates. After adding the Potassium Thiocyante to all the liquids we got different results for each. For the distilled water we got no reaction meaning there were no presence of Iron ions in it. For the control we got precipitates and the water turned a dark red color which meant there was a presence of Iron ions.  When Potassium Thiocyante  is added to the ocean water, there was no reaction, meaning there was no presence of Iron ions in the water. For the tap water, there was also no reaction. In this test which was testing for Iron Ions, we only saw Iron Ions in the control, but not any of the other liquids.

          The third test was testing for Chloride Ion (Cl^-). Using the exact same types of water was before, but like the last test, we are adding a different chemical to the liquids.  The chemical we are adding is Silver Nitrate. When silver nitrate is added to the reference, which was ferris Sulfate, the liquid turns a white cloudy color, with precipitates. In the distilled water, after adding the Silver nitrate there was no reaction, concluding to no Chloride Ions. When the Silver nitrate was added to the ocean water, the water changed to a white cloudy color, with precipitates, concluding to a presence of Chloride Ions. For the  tap water, when the Silver nitrate was added, turned a little cloudy, but not a lot, and a small presence of precipitates. The conclusion to the third test is that the control, ocean water, and tap water had a presence of Chloride Ions in it, but distilled water had no Chloride Ions in it.

            The forth test was testing for Sulfate Ion (SO₄2-). This test also used the exact same types of water, that all the other tests used, and just like the other test, the chemical that will be added to the liquid is different than the chemicals that were added to the previous samples. The chemical that will be used is Barium Chloride. When barium chloride is added to the reference water, a little bit of white particles appear. So now we know that if in any of the samples little white particles, precipitates, appears we know that there is a presence of Sulfate Ions in it. In the control, after we added three drops of barium chloride, we saw little white precipitates. In the distilled water, there was no reaction. In the ocean water there were little white precipitates.  In the tap water nothing happen. Concluding that the ocean water, the control have Sulfate Ions in the liquid, but the distilled water and the tap water have no sulfate ions in them.

Procedure:
-First obtain all chemicals and materials. Obtain the distilled water, the ocean water and the control, then retrieve the chemicals; Ferric Nitrate solutions, Ferrous Sulfate solution, Sodium Carbonate solution, Barium Chloride solution, Potassium Thiocyanate solution, Calcium Chloride solution and Silver Nitrate. Also obtain the well plate and stir rod. 

-Then add 20 drops of distilled water into the first well in the well plate, and label the well "Distilled Water." After adding the distilled water into the well, add three drops of sodium carbonate into the same well with the distilled water.

-Next add 20 drops of the control liquid into the second well, and label the well "C" for control. -After adding the control into the well add three drops of Sodium Carbonate to the control.

-After finishing the control, add 20 drops of ocean water into the third well, and label that well "Ocean Water." Then add three drops of Sodium Carbonate into the ocean water.

-Then add 20 drops of calcium carbonate as a reference, into the forth well. After, add three drops of sodium carbonate into to calcium carbonate.

-Next add 20 drops of tap water into the fifth well, and then add three drops of sodium carbonate.

When the first test is done rinse the well plate and then stir rod thoroughly.

Second test:

-Add 20 drops of distilled water into the first well, then add three drops of Potassium Thiocyante to the distilled water

-Then add 20 drops of the control into the second well, then add 3 drops of potassium Thiocyante to the control

-After that add 20 drops of ocean water into the third well, and the add 3 drops of Potassium Thiocyante to the ocean water

-Add 20 drops of ferrous Sulfate, as the reference, into the forth well, and add three drops of Potassium Thiocyante

-Into another well add 20 drops of tap water into the fitfh , then add three drops of Potassium Thiocyante into the tap water

When the second test is done rinse the well plate and then stir rod thoroughly

Third Test:

-Add 20 drops of distilled water into the first well, then add three drops of silver nitrate into the distilled water

-Then add 20 drops of the control into the second well, and then add three drops of the silver nitrate into the control

-Next put 20 drops of ocean water into the third well, and then add three drops of silver nitrate into the ocean water.

-Then put 20 drops of tap water into the the forth well, and then add three drops of silver nitrate into the tap water.

Farris sulfate

Results:

For the Calcium Ion test we got to the conclusion that the control, and the ocean water had a Calcium Ions in it, and the rest of the liquids didn't have the Calcium Ion in it.

For the Iron(III) Ion test we came to the conclusion that only the control had a presence of Iron Ions in it, because that was the only liquid that turned the same color as the reference. The rest stayed the same.

For the Chloride Ion Test we came to the conclusion, that the ocean water, the control, and the tap water all had Chloride Ions in it. But the distilled water was non reactant witch meant that there weren't andy Chloride Ions in the water.

For the Sulfate ion test we came to the conclusion that the ocean water, and the control had the Sulfate ions in them. The distilled and tap water were  non reactant, which meant they did not have the sulfate ions in them.

Questions:

1. Why were a reference solution and a blank used in each test?

A reference solution is used to reffere all the other samples, to see if there is a presence of ions in the liquid. A blank is used to show what a non-reaction looks like.

2.What are some possible problems associated without he use of qualitative tests?

One possible problem could be that the sample isn't clear, and it is not easy to recognize if there are particles in the sample or not.

3. These test cannot absolutely confirm the absence of an ion. Why?

Because there is no test for an absence

4. How might your observations have changed if you had not cleaned your wells or stirring rod thoroughly after each test?

If after each test we didn't thoroughly clean the wells we could have accidentally mixed some chemicals, causing the samples to react differently.