The purpose of this experiment was to identify the two components of an unknown mixture through diverse experimental techniques such as recrystallization, extraction, melting point, and acid-base reactions. From this, the group to which these two compounds belong to had to be determined. These groups are: Carboxylic Acids, phenols, and neutrals. By determining the melting points of the two unknown compounds, these values were compared to the values of melting points in the chart and the proper compound was selected. For the case of this experiment, the unknown mixture contained, 4-methylbenzoic acid. The neutral was not determined due to inaccuracies during the experiment. Introduction: In order to test the purpose- to determine an unknown …show more content…
These tend to be very strong acids due to physical properties. The pKa values of these acids typically ranges between 4 and 5. Phenols are organic compounds that consist of a hydroxyl group, -OH. These compounds are generally weak acids with a pKa of approximately 10. A good way to show how these kind of molecules work is shown in the below reactions. Both of these reactions involves an acid reacting with a sodium bicarbonate, NaHCO3. The pKa value of this compound is around 6.4. looking at the first reaction and comparing the pKa values of the carboxylic acid and the sodium bicarbonate, (4-5, and 6.4 respectively), it can be seen that the sodium bicarbonate will act as a base, due to a higher pKa value, and the reaction will proceed to create a conjugate base and acid. On the other hand, looking at the second equation, it is evident that the phenol when reacted with sodium bicarbonate will act as a base. This is due to sodium bicarbonate having a lower pKa value. This example helps show that through acid-base reactions, and the use of a strong base, the type of unknown mixture can be determined to be either a phenol or carboxylic
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.
The hypothesis that was provided to this question was If Phenol Red is add with the other chemicals then a color change will occur. Methods: To begin the lab 40 mL of Phenol red were obtained in a beaker, and 40 mL of water were obtained in a separate beaker. Next one plastic baggie was
In addition, my hypothesis for this lab is the cornstarch and water will make a liquid-solid substance. The Investigating Mixtures Lab objective is to observe that not all liquids behave the same way when mixed with other liquids. Also, my hypothesis for this lab is the vegetable oil will not mix with the water. Conclusion/Analysis:
Determining the Identity of an Unknown White Compound Maxwell Yurs Group Member: E.B. Floersch, Alexander Medina, and Masih Horri College Science and Engineering University of Minnesota, Minneapolis October 12, 2014 The experiments that were completed were used to determine the identity of an unknown white compound to allow for proper disposal. These experiments included flame tests, pH tests, and conductivity tests. After each was completed, it was found that the identity of the white compound was Sodium Nitrate.
ST Report In the experiment, the problem was the contaminants that were affecting the quality of the water samples. To fix this issue, three scientists had to determine the contaminants that were present in the samples. One sample was from the school sink and the second sample was from an unknown source. The scientists conducted many tests to figure out what pollutants were present in the water.
2-methyl-1-propene 4. A student left a mixture of some alkyl halides (RCI and RBr) in an open container for
When the substance reacted with the solution it turned from its initial color yellow/brown to its final color lilac/violet. The experiment went by easily flowing nicely, although one or two things went wrong, none had any effect on the experiment. It is very important to know what foods are composed of because, knowing what is inside our food is essential for our health. We need to be aware of what things we are consuming and what we should be consuming for our bodies to function properly.
The three-component mixture was separated through the isolation of each individual component. The isolation process began with o-toluidine, which utilized the addition of hydrochloric acid, sodium hydroxide, and dichloromethane—to the mixture—for the formation of an organic layer that contained pure o-toluidine. Then, the addition of sodium hydroxide and hydrochloric acid to the remaining mixture resulted in an organic layer, which contained pure benzoic acid precipitate. Finally, anhydrous magnesium sulfate and methylene chloride were added to the remaining mixture of anisole, which resulted in a pure anisole because it removed all residual water and boiled off excess methylene chloride used. The percent recovered from extracted anisole, benzoic
Abstract: The purpose of this experiment was to identify given Unknown White Compound by conducting various test and learning how to use lab techniques. Tests that are used during this experiment were a flame test, ion test, pH test, and conductivity test. The results drawn from these tests confirmed the identity of the Unknown White Compound to be sodium acetate (NaC2H3O2) because there were no presence of ions and sodium has a strong persistent orange color. The compound then will be synthesized with the compounds Na2CO3 and HC2H3O2 to find percent yield.
Exercise 14: Unknown Identification Lab Report The purpose of the study was to identify the unknown bacterium using various biochemical tests in addition to using scientific methods in determining the outcome of the hypothesis. Each biochemical test will help determine the bacteria based on specific characteristics of each organism. I was giving unknown number 232. The first procedure that needed to be done after obtaining unknown bacterial mixture was to isolate the two bacteria in a pure culture using the streak plate method described in Microbiology Laboratory Manual Eight Edition. The material used was trypticase soy agar (TSA) plate, nutrient plate, starch agar, hydrogen peroxide, iodine reagent and microscope.
The flame test produced inconclusive results because we were unable to determine whether the flame produced a faint orange tint or no color. Next we tested the pH change that the compound caused in water to determine its solubility. Our known compound did not dissociate or dissolve in water, instead it formed a white colored precipitate, therefore that eliminated a lot of the choices from the unknown compound list. In addition, when we performed the acid test, the unknown compound bubble which revealed it must be a carbonate. The previous test reveal it did not dissociate in water, therefore the only option from the list it could be was
The possible explanations and changes to make are similar to the previous questions. Conclusion and Future Experiment 18. The identity of the product and unknown were 4-tert-butylbenzyl phenol ether and tert-butyl phenol respectively. The key to making this discovery was the melting point and TLC results!
Resulting in the experiment that the unknown compound was chorine. Introduction As a groups to identify an unknown compound, we need to know its physical properties (color, state and smell). David brought all the compound that are need to for the project and
Acids are proton donors in chemical reactions which increase the number of hydrogen ions in a solution while bases are proton acceptors in reactions which reduce the number of hydrogen ions in a solution. Therefore, an acidic solution has more hydrogen ions than a basic solution; and basic solution has more hydroxide ions than an acidic solution. Acid substances taste sour. They have a pH lower than 7 and turns blue litmus paper into red. Meanwhile, bases are slippery and taste bitter.
Abstract The unknown concentration of benzoic acid used when titrated with standardized 0.1031M NaOH and the solubility was calculated at two different temperatures (20◦C and 30◦C). With the aid of the Van’t Hoff equation, the enthalpy of solution of benzoic acid at those temperatures was determined as 10.82 KJ. This compares well with the value of 10.27KJ found in the literature.