The Analysis Of Unknown Compounds

The primary goal of this laboratory is to correctly identify an unknown substance. To achieve this task, one may use various tests that reveal both chemical and physical properties of a substance. By comparing the results of a known substance and the unknown substance, one may eliminate alternative possibilities and more accurately predict the undisclosed compound. Furthermore, by performing these tests, data can be collected and verified regarding chemical and physical properties of the unknown. Understanding the chemical properties of a known substance aids one’s understanding of the unknown based on comparative analysis of the results of the tests.

Purpose: To use indicators to test for the presence of organic compounds in certain substances.

Eleven mystery test tubes labeled from K-1 to K-11 contained: 6M H2SO4, 6M NH3, 6M HCl, 6M NaOH, 1M NaCl, 1M Fe(NO3)3, 1M NiSO4, 1M AgNO3, 1M KSCN, 1M Ba(NO3)2, 1M Cu(NO3)2 respectively. The contents of the test tubes were determined by chemical experiments. Solution K-1 contained NiSO4 because when solution K-9, ammonia which was identified by its pungent odor, was added, an inky dark blue color was made. Iron (Fe (NO3)3) was determined to be in test tube K-2. KSCN was found in test tube K-11 since Fe (NO3)3 and KSCN makes a bloody color when mixed together. Flame tests were conducted in which K-8

In order to test the hypothesis, the same tests given in Table 1 and Table 2 were performed on a sample of calcium nitrate. The results obtained for all the tests were the same as with our unknown compound. To further test this hypothesis, five different reactions were designed, as can be seen in Table 3, in which a

Procedure: Filled each test tube with substances provided and subjected them to various conditions. These conditions included, heat, cold water, hot water, acid and basic additions and tested on litmus paper. The reactions were observed and documented at each step.

The City of Mounds View, located in the northwest corner of Ramsey County, Minnesota, contains a residential population of over 12,000 and over 150 businesses. The city is situated at the connection of Interstate 35W and State Hwy 10, and is conveniently ten miles from Minneapolis and St. Paul. Mounds View is renowned for its large, wooded residential lots and wide housing variations. The city has a total area of 4.12 square miles, of which 4.03 square miles is land and 0.09 square miles is water.

Seven test tubes were labeled numerically with 2 mL of VO3- and H2SO42- added to each tube. A small pea size portion of solid Na2SO3 was added to the first test tube. Then, 20 drops of distilled water were added to the second test tube. In the third test tube, 20 drops of (.2 M) NaBr were added. Then, to drops of (.2 M) NaNO2 were added into the fourth test tube. A small portion of Fe(NH4)2(SO4)2 * 6H2O was added into the fifth test tube. The sixth test tube had 20 drops of (.2 M) H2Cr2O4 added, where the seventh test tube was the control tube with no additional chemicals added. All the test tubes were left to react for 3 minutes and then heated in a heated bath for approximately 20 minutes.

In this experiment, the identity of an unknown compound will be deduced from analysis of physical properties, boiling points, IR spectra, chemical tests, and melting points of derivatives. This experiment allows for individual selection of chemical tests, order of steps, and additional analysis, as necessary, based on what is needed to determine identity of unknown.

Aim: To classify unknown substances according to their structure type and to observe how the structure of materials affects their uses.

The guiding question of this ADI lab was, “What are the identities of the unknown compounds?” The goal of this lab was to understand the relationships between moles and molar mass to find the identity of unknown compounds. The mole can be used to measure small amounts of a substance or is used to convert from unit to unit using dimensional analysis. One mole is equivalent to the molar mass in grams of that substance. If you start with the moles of an unknown substance, multiply it by a given compound’s molar mass, and then divide it by however many moles are in the compound of your choice, you will get the mass of the compound. With that answer you can then compare with mass of the compound in the bag to determine its identity. We first started

When holding the wire in the Bunsen flame, which had been previously dipped in the unknown solution, the edge of the flame appeared to emit a pale green color, which would indicate that our unknown sample would contain the element barium. This conclusion was incorrect and upon redoing the Flame test and making the unknown solution more concentrated by adding less water, it was found that the edge of the flame was actually pale violet in color, indicating that the element in our sample was potassium. Additionally, in week 1, our group encountered another error while analyzing the properties of our unknown sample through the anion tests. The two cation tests; Flame and Ammonium concluded that the first element in our compound was in fact potassium.

The main objective of this experiment is to carry out qualitative analysis to identify metal cations in unknown solution 1.

The cations in both the known and unknown samples were identified by using qualitative analysis, of which were determined to be acidic, basic, or neutral by using litmus paper. Acid-base reactions, oxidation-reduction reactions, and the formation of complex ions are often used in a systematic way for either separating ions or for determining the presence of specific ions. When white precipitate formed after adding hydroxide, aluminum ion was determined to be present in the solution. However, nickel was determined to test positive when the solution changed to a hot pink color after adding a few drops of dimethylglyoxime reagent and iron was present when the solution was a reddish brown color when sodium hydroxide was added to the mixture at the very beginning of the experiment. Qualitative analysis determines that ions will undergo specific chemical reactions with certain reagents to yield observable products to detect the presence of specific ions in an aqueous solution where precipitation reactions play a major role. The qualitative analysis of ions in a mixture must add reagents that exploit the more general properties of ions to separate major groups of ions, separate major groups into subgroups with reactions that will distinguish less general properties, and add reagents that will specifically confirm the presence of individual

12. The crocodile clips are attached to the copper electrodes of the experimental apparatus and the power supply is turned on. Simultaneously, the stopclock is started. The thermometer is checked every 30s. 13. After 300s the stopclock is stopped and the power supply is turned off. The negative cathode is carefully removed and is dried using a hair dryer. 14. When dry the negative cathode is placed on the electronic milligram balance and its final mass is recorded. 15. The positive anode and negative anode of the experimental apparatus are disposed and the electrolyte is poured out to ensure that the anode slime (impurities) does not contaminate the solution. 16. The electrodes of the experimental apparatus are replaced with new copper strips. 17. Steps 7 to 16 are repeated. However, this time, the rheostat is adjusted using the calibration apparatus until the multimeter shows approximate readings of 0.40 A, 0.60 A, 0.80 A and 1.00 A respectively. 18. Time permitting, the entire experiment is repeated. Safety Copper sulphate may cause irritation and burns if it comes into contact with the eyes. As standard lab procedure, safety goggles and lab coats must be worn at all times. Control of Variables Volume of Electrolyte Used

Organic compounds are, by definition, any chemical compound containing carbon. These compounds include carbohydrates, polysaccharides, lipids, proteins, and nucleic acids. Each one of these compounds has a different purpose. Carbohydrates give energy to cells when consumed. Lipids are basically the fats of a cell. Proteins are the building blocks of muscle in a cell. Nucleic acids are used to transfer genetic information from one cell to the other.