Goals The primary goal of this experiment was to identify an unknown compound by running various tests to determine the qualitative solubility, conductivity, and pH value of the compound. Tests were also performed for the presence of specific cations and anions in the compound. The second goal was to discover the reactivity of the unknown compound by reacting it with different types of substances. The third goal of this project was to calculate the quantitative solubility of the unknown compound in water. The last goal was to determine the percent yield of a product formed during a reaction with the unknown compound. Experimental Design The first day of lab consisted of various preliminary tests that helped identify the unknown compound. …show more content…
To test for the presence of the ammonia cation, a scoop of the unknown compound was mixed with NaOH to see if the resulting solution had a noticeable smell that would affirm the presence of ammonia. A moist piece of pH paper was then held near the solution to see if the ammonium would dissolve the water on the pH paper. The next cation test performed was the flame test. A gram of the unknown compound was held by a metal stick above the flame of a Bunsen burner to see what color flame the compound would produce. The chart in the lab manual on page 63 was used to determine what cation correlated with what flame color. The anion tests followed the cation tests. To test for the presence of the chloride (Cl-) anion, a small scoop of the unknown compound was mixed with 1 mL of water in a test tube to create a solution. Then, 1 mL of 6 M nitric acid (HNO3) and 1 mL of silver nitrate (Ag(NO3)2) solution were added to the test tube to see if a white precipitate formed. To test for the presence of the sulfate (SO42-) anion, a small scoop of the unknown compound was mixed with 1 mL of water in a test tube to create a solution. Then, 1 mL of 6 M hydrochloric acid (HCl) and 1 mL of barium chloride (BaCl2) solution were added to the test tube to see if a white precipitate formed. To test for the presence of the carbonate (CO32-) anion, a small scoop of the unknown compound was mixed with …show more content…
The unknown compound was first reacted with an acid. To begin, 0.50 grams of KCl was mixed with 5 mL of water. Then, 1 mL of 6 M H2SO4 was added to the solution. Secondly, the unknown compound was reacted with a base. Exactly 0.50 grams of KCl was mixed with 5 mL of water, and 1 mL of 1 M NaOH was added to the solution next. Lastly, the unknown compound was reacted with two different salts. For the first salt, 0.50 grams of KCl was mixed with 5 mL of water in one beaker while 0.5 grams of NaNO3 was mixed with 5 mL of water in a different beaker. Then, the NaNO3 solution was added to the KCl solution. To perform the reaction with the second salt, 0.50 grams of KCl was mixed with 5 mL of water and 1 mL of 1 M Ag(NO3)2 was added. After performing each reaction, the solution was observed to see if a reaction occurred and the pH value of the resulting solution was tested using a pH
The purpose of this lab was to be able to use physical characteristics to determine the identity of an unknown compound. The data from this experiment classified aluminum as metallic; ascorbic acid, paraffin, palmitic acid, sucrose, graphite, and water as molecular; sodium chloride as ionic. In order to determine this, 3 tests were conducted. The first test was to test the conductivity of each substance at room temperature. In this test, only graphite and aluminum conducted.
Metal cations can be identified based on the colors they emitted off when heated in a flame.1 When atoms of the ions that were tested are excited, their electrons move up to higher levels of energy.2 When the electrons relax and return to the original states, they emit photons of specific energy creating wavelengths of light that produces colors.3 The test wire and Bunsen Burner were used to excite the solution in the crucible. The standard metal cations that were tested and their outcomes are as shown in Table 1.
The final step was to synthesize potassium nitrate using silver nitrate and potassium chloride. The experiments listed above concluded the unknown white compound to be potassium nitrate. Interestingly, the work’s main goal is to follow lab safety and properly dispose
Materials I used. Were a petri dish, scapula, liquids, burner, C-clamp, tongs, gas to start the flame, eight different types of powders, and the most importa martial was our goggles for safety. The petri dish was used to put the powder in for testing. The scapula was used for scooping up the powders.
The compounds tested in included the unknown, Calcium Nitrate, Calcium Chloride, Calcium Carbonate, Sodium Chloride, Potassium Chloride, Magnesium Chloride, and Ammonium Chloride. The next test was the pH test. In this test, the aqueous solutions from the flame tests were used again. A piece of pH paper was dipped into the aqueous solutions, a different piece for each solution. The ensuing coloration of the paper was compared to the pH scale and the
Sodium Bicarbonate mixed with Hydrochloric acid. The chemical reaction observed showed that there was fizzing and bubbling, this is evidence that a new gas was being produced. This new gas, CO2 was generated from the reaction. After the fizzing stopped a liquid was leftover leading me to conclude the liquid leftover leading me to conclude the liquid leftover was the NaCl and H2O 4. You found a sample of a solution that has a faint odor resembling vinegar (an acid).
In attempt to identify Unknown A three different reagents were used. In the first test five drops of NaOH was added to Unknown A, no apparent reaction occurred therefore there was no cation present. Another fraction of Unknown A was tested with diluted HNO3 and five drops of AgNO3 which formed a yellow precipitate however, it was later discovered that this test was a false positive for anions. A final fraction of Unknown A was tested with five drops of HCl to test for CO3 anions. The result of this test was effervescence (bubbles), this suggested that Unknown A was positive for CO3.
A drop of bromothymol blue was added to the mixture which serves as an indication if the mixture would be completely neutralized with the addition of 6M sodium hydroxide. Then, 9 drops of 6M sodium hydroxide was added to the flask to neutralize the mixture. A significant color change was
Next, a 100 mL graduated cylinder was used to measure 60 mL of distilled water. The water was added to the compound and stirred with a glass-stirring rod until dissolved. Next, The flame test required the solution made during the solubility test. The experiment needed a metal wire that was dipped into the solution
Ion-exchange columns are prominent in research labs to target and remove certain ions from a solution or mixture (2). Essentially, an ion exchange column will exchange the K+ with the H+ ions and will result in a solution of hydrogen ions and the iron-oxalate anion. After this, an acid-base titration will be conducted. The hypothesis of this lab is that the creation of a coordination compound can help determine an unknown formula by determining the percent composition and conducting titration of the ions present in the
I put distilled water into a section of my well plate and added a small scoop of my compound into it. Another reason that I decided to do it first was that once dissolved, I put the conductivity meter into the well plate which was the most time efficient. Once I conclusively figured out my compound was ionic I moved on to the flame test. The flame test only works on ionic compounds, so doing it after knowing that the test would return helpful evidence made the most sense. After all three of these tests, there was enough evidence to make a conclusive answer to the original question of, what compound is
Through the identifications of cation and anions, students will discover the unknown ionic compound that is given to them. Materials and Methods: In part one of the experiment, materials were gathered: 10 centrifuge tubes, test tube rack, distilled water bottle, disposable pipets, cobalt glass, nichrome wire loop, striker, 50mL beaker, Bunsen burner and striker, ring stand,
Part B’s focus was identifying barium or calcium in the unknown metal nitrate solution. The qualitative analysis scheme Part C utilized a different qualitative analysis scheme, the cation ion flame
Abstract: The purpose of this experiment was identifying two compounds in an unknown mixture via liquid-liquid extraction and acid-base reactions. The compounds in the unknown mixture isolated by using recrystallization, and then their identity was determined by comparing the experimental melting point values with actual melting points. Unknown mixture 5 contained a carboxylic acid, 4-methylbanzoic acid, and a non-ionizable organic compound, 1,2-diphenylethane-1,2-dione.
Experiment 8: Identification of metal ions and inorganic compounds in aqueous solution Introduction: Qualitative analysis is the identification a sample's component(s). Unlike a quantitative analysis, we are not concerned with the amount of a substance present in a sample but only with its identity. In this exercise we will focus on identifying the cations and anions that make up ionic compounds, both solid and in solution. Ideally there would be chemical tests that could be used to identify individual ions without interference by any other ions. Unfortunately, there are often complications.