Archives for October 2007

Personality Assessment #1

One of the careers suggested for me that I researched about was ballistics expert. A ballistics expert’s duties include analyzing bullets and bullet fragments, gun powder, and anything else relating to firearms found at crime scenes. They compare evidence found at the crime scene to fabricated evidence made in the lab to learn more about the actual evidence. The fabricated evidence is made by test firing guns. The two evidences are usually compared using a microscope. Ballistic experts also testify in court to show their finding and explain how the suspect used their firearms during the crime.

According to the personality and life value test, it says I tend to think things through before acting and that I like to have a good understanding of the ideas behind a job or situation. I suppose these aspects of my personality would bode for this job. A ballistics expert needs to thoroughly examine all the evidence before making and conclusions. It seems like a meticulous process of going through evidence and testing it against fabricated lab evidence, but I would definitely be able to deal with all of that. I enjoy carefully going through data and analyzing it to come up with a final solution. Doing research and piecing information together for a practical solution is just something that gives me satisfaction.

The personality and life value test also reported that I “…tend to be realistic and practical and are careful with facts and details.” Again, this just emphasizes how I would scrupulously have to examine evidence and data. I am an organized person, so keeping facts straight would not be a problem. The test also said that I “…draw upon past experience and prefer to use proven and established procedures.” This would have to be the case as a ballistics expert because they do not create new techniques for analyzing evidence; they most likely use proven procedures for all examinations. There does not seem to be much room for creativity, but I would be ok with that because I like structure.

Overall I do not think that I would like to actually do this job. Learning about crime scenes may be interesting at first but it could get disheartening after a while. Also the work environment seems like it would be depressing because you are by yourself most of the time firing guns and looking under microscopes. I do not think I would be able to deal with that day in and day out. The job definitely does fit many of my personality traits, but I do not think it would be right for me.

Personality Assessment #2

1. What where your overall results on the Big Five Personality Factor Test?

In regards to the extraversion portion of the test, it reported that I am introverted and that I prefer solitary activities and social with predominantly a few close friends. I scored low on extraversion (16), friendliness (10), gregariousness (5), and excitement seeking (7). I scored average on assertiveness (59), activity level (55), and cheerfulness (36).

In regards to the agreeableness portion, I scored low and the test reported that I show more concern for myself than others and that people see me as tough, critical, and uncompromising. I scored very low on agreeableness (5), trust (7), morality (13), altruism (14), modesty (10), and sympathy (0). I scored highly on cooperation (69).

In regards to the conscientiousness section of the test, I scored very highly. The test reported that I set clear goals and pursue them with determination. It also said that people regard me as reliable and hard-working. I scored very high on conscientiousness (99), self-efficiency (98), orderliness (98), dutifulness (71), achievement striving (80), self-discipline (99), and cautiousness (99).

In regards to the neuroticism section, I scored low, which indicates that I am calm, composed, and unflappable. I scored low on neuroticism (6), anxiety (17), anger (1), depression (21), immoderation (2), and vulnerability (3). I scored high on self-consciousness (81).

Finally, in regards to the openness to experience portion, I scored fairly low which indicates that I like to think in simple terms and that I am down-to-earth and practical. I scored low on openness to experience (8), imagination (4), emotionality (24), adventurousness (1), and intellect (4). I scored average on artistic interests (45) and high on liberalism (73).

2. After reading your profile, what statements about you contained in your profile accurately fit you? Give at least 1 example from your own life for each of the 5 personality factors.

Pretty much everything reported seemed accurate. From the extraversion section, I scored low and it reported that I am introverted which is true. I do not make new friends very easily; it takes me some time before I become comfortable with new people. From the agreeableness section, I scored low which means I have more concern for myself than others. I do not like to admit to that, but it probably is true. I almost always put myself ahead of other people and I have low sympathy for other’s problems. There was a question about your level of sympathy for homeless people on the test and I have absolutely no sympathy for them, I go to the city a lot and I just cannot stand it when they ask me for change.

From the conscientiousness section, I scored very high which means I am a hard worker and that I set goals and purse them with determination. This is definitely very true. Whenever I have a task at hand, I will sit down and work at it until I am finished. For example, I have been working on this assignment straight through without any major time breaks. I want to get it done before I do anything else. From the neuroticism section, I scored very low which indicated that I am very calm and composed. I would have to say this is true. I have a very even keel and I do not overreact emotionally to anything. A lot of my friends have made comments to me about how hard it is to get me riled up about anything. Finally, in regards to the openness to experience section, I scored low which indicates that I like to think in simple terms and that I am down-to-earth. I would say this is true too because I never try to overcomplicate things. Whenever I think, I try to break things down so it is easier for me to analyze events and situations. I never make mountains out of mole-hills.

3. After reading your “Personal Evaluation,” what statements about you contained in your profile were inaccurate? Give at least 1 example from your own life.

Surprisingly, I feel that almost everything reported is dead on about my personality. The only thing that I do not really agree with is my level of artistic interest. I scored a 45 which is average, but I would say I am highly interested in arts. I appreciate artwork and do notice details about art that other people do not notice. I am also really into music and play two instruments. Music is a huge part of my life, and I am pretty sure music counts as part of the arts. That is the only score I had a problem with. I would have to say that all of my other scores seemed very reasonable.

4. Explain how you will be able to apply what you learned from this activity to your own life. That is, in what ways can you use the information learned from this activity?

I pretty much knew all these aspects about my personality, but this test puts them out in the open for me to see. I can use this information to improve my personality. For example, I would like to be less introverted, so I am going to try and work on that aspect of my personality. I am also going to try working on my compassion for other people; this test really showed me how much I put myself ahead of other people.

5. Any other comments about the test or your results?

I felt this was a fairly comprehensive test. It was 120 questions which is a lot, and it also reiterated a few questions to ensure consistency, so I feel that it was a quality questionnaire.

I. Introduction

A. Objective

The purpose of this experiment is to isolate cholesterol from gallstones via the techniques of extraction and recrystallization. The gallstones will first be dissolved in 2-butanone heated in a hot sand bath. The solution will then be transferred to a micro column using a pipet to filter out the bilirubin, which is the primary impurity of gallstones. The remaining 2-butanone will be removed and the crude cholesterol left over will be recrystallized by dissolving it with methanol and centrifuging it in a Craig tube.

B. Materials and Safety

C. Experimental Procedure

A sample of crushed gallstones weighing about 100 mg will be obtained and weighed. The crushed gallstones will then be placed in a 10 x 100 nm reaction tube along with a boiling stick and 1.5 mL of 2-butanone. This mixture will be gently heated in a hot sand bath. In a second reaction tube also containing a boiling stick, 1.0 mL of 2-butanone will be heated until it is boiling. When the gallstones have disintegrated and the cholesterol has dissolved in the first reaction tube, it will be filtered through a micro column. The micro column will be prepared from a Pasteur pipet packed with a loose wad of cotton, 2 mm of sand, 3-4 mm of anhydrous magnesium sulfate, 1 cm of anhydrous sodium sulfate, 1 cm of Norit RO 0.8 activated carbon pellets, and a very small piece of cotton. The micro column will be clamped in a vertical position and will have a weighed and cleaned 10 x 100 mm reaction tube beneath it.

The solution in the original reaction tube will be transferred into the micro column using a warm Pasteur pipet, which is warmed by immersing it in the hot vapors of the boiling 2-butanone. The 1.0 mL of boiling 2-butanone will be used to wash out the original reaction tube and pipet into the micro column. The filtered hot solution of 2-butanone solution will then be warmed in a sand bath and the 2-butanone will be removed under a gentle stream of nitrogen. The crude cholesterol will be scraped from the reaction tube onto a previously tared piece of a creased, glazed weighing paper. After obtaining the weight of the crude cholesterol, it will be placed into a Craig tube. To recrystallize the cholesterol, it will be first dissolved in the minimum amount of hot methanol. The solution will then be allowed to slowly cool to room temperature, and it will then be cooled in an ice bath. The crystalline cholesterol will be isolated via centrifugation. The cholesterol will then be allowed to air dry. It will then be weighed and its melting point will be determined.

II. Experiment and Results

A. Data

First, a sample of crushed gallstones weighing 0.131 g was obtained. Next, a micro column was prepared using a Pasteur pipet packed with a loose wad of cotton, about 2 mm of sand, about 3 to 4 mm of anhydrous magnesium sulfate, about 1 cm of anhydrous sodium sulfate, about 1 cm of Norit RO 0.8 activated carbon pellets, and a small piece of cotton. One prepared, the micro column was clamped vertically on a ring stand. The crushed gallstones were then placed in a clean glass centrifuge tube along with a boiling stick and 1.5 mL of 2-butanone. The solution was gently heated in a sand bath, along with a separate centrifuge tube containing about 1.0 mL of 2-butanone. One the gallstones dissolved, the solution was transferred to the micro column using a warm pipet. The pipet was warmed by immersing it into the hot vapors of the second tube containing boiling 2-butanone. The reaction tube was rinsed with the hot 2-butanone and the remaining solution was filtered in the micro column.

The filtrate was collected in a clean centrifuge tube. The 2-butanone was removed from this tube under a stream of nitrogen and the remaining cholesterol was allowed to air dry for a week. A minimum amount of methanol was added to the cholesterol and the tube was heated in a sand bath along with a boiling stick until the cholesterol dissolved. The solution was then allowed to cool to room temperature and was then put into an ice bath to cool more. The crystalline cholesterol formed was isolated via centrifugation. The crystals were removed from the tube using a spatula onto filter paper and the crystals were allowed to air dry for a week.

III. Conclusions

Without knowing my final weight and melting point of the crystalline cholesterol, I can only discuss possible sources of error during the procedure. When preparing the micro column, if the wrong amount of any of the materials was added, the bilirubin may not have filtered out. This make the amount of cholesterol recovered be less than expected because the cholesterol may not have crystallized if the bilirubin was still in the solution. If the filtered solution was cooled too fast, that may have prevented the formation of crystalline cholesterol, too.

I. Introduction

A. Objective

The purpose of this experiment is to separate a prepared mixture of benzoic acid, 4-nitroaniline, and naphthalene by the technique of extraction. The compounds will be extracted on the basis of the solubility properties of the acids, bases, and their salts. The given unknown sample will be dissolved with dichloromethane. Hydrochloric acid will then be added and extraction of p-nitroaniline will be performed in two steps: mixing and separation. The extracted p-nitroaniline will then be isolated by adding aqueous sodium hydroxide which will turn the solution basic which will cause the p-nitroaniline to precipitate. The benzoic acid will be extracted by adding sodium hydroxide to the dichloromethane solution and using the process of separation. The benzoic acid will then be isolated using aqueous hydrochloric acid to turn the solution acidic which will make the benzoic acid precipitate. These two precipitates will be collected using vacuum filtration. The 4-nitroaniline will be recrystallized using boiling water, and will then be weighed and measured for its melting point. The benzoic acid will also be recrystallized using boiling water, and will then be weighed and measured for its melting point. Anhydrous sodium sulfate will be added to the left over dichloromethane solution. The mixture will react and then be filtered, and the solid residue of naphthalene will be weighed.

B. Materials and Safety

C. Experimental Procedure

A prepared mixture of unknown relative amounts benzoic acid, 4-nitroaniline, and naphthalene will first be obtained. The weight of the mixture will be taken and recorded. The sample will then be transferred to a 15 mL glass centrifuge tube. 3.0 mL of dichloromethane will then be added to the tube and the mixture will be dissolved by shaking the tube gently. Next, 1.5 mL of 6 M aqueous hydrochloric acid will be added to the centrifuge tube. The mixture will be mixed by capping the tube and shaking it by hand to thoroughly mix the two phases. The centrifuge tube will then be vented by loosening the cap, and then it will be clamped to allow the two phases to separate. The dichloromethane layer will be separated using a pipet with bulb on top. The dichloromethane layer will be sucked into the pipet and transferred to a reaction tube. The left over aqueous layer will be transferred into a 20 x 80 mm vial labeled “aqueous acid extracts” in the same manner using a new pipet. The dichloromethane layer will then be transferred back to the centrifuge tube using a pipet. This technique will be repeated by adding another 1.5 mL of 6 M aqueous hydrochloric acid to the centrifuge tube as before.

Next, 1.5 mL of cold 3 M sodium hydroxide solution will be added to the centrifuge tube with dichloromethane. The same procedure will be followed as above for mixing and separating, except this time the aqueous layer will be transferred to a 20 x 80 mm vial labeled “aqueous hydroxide extracts”.

After that, 12 M aqueous hydrochloric acid will be added to the 20 x 80 mm vial labeled “aqueous hydroxide extracts” dropwise until the solution is acidic. The vial will be placed in an ice bath while this takes place. Next, 6 M aqueous sodium hydroxide will be added dropwise to the vial labeled “aqueous acid extracts” until the solution is basic. This will also take place in an ice bath. The solid formed by these steps will be separately filtered via vacuum filtration using a 25 mL filter flask. The precipitates, benzoic acid and p-nitroaniline, will be transferred to filter paper and allowed to dry, then will be weighed. If specified, 4-nitroaniline and benzoic acid will be recrystallized from boiling water. These samples would then be dried, weighed, and have their melting points determined.

The dichloromethane solution will then be dried by adding about 0.3 g of anhydrous sodium sulfate to the centrifuge tube. The tube will be briefly shaken and allowed to stand for 5 minutes with occasional swirling. Finally, the dichloromethane solution will be filtered or decanted into a tared reaction tube under the hood. The weight of the solid residue in the reaction tube will be determined and the tube will be stoppered. If specified, the solid residue will be purified by column chromatography.

II. Experiment and Results

A. Data

A sample comprised of a mixture of unknown proportions of benzoic acid, 4-nitroaniline (p-nitroaniline), and naphthalene weighing 0.292 g was obtained. The sample was transferred into a 15 mL glass centrifuge tube along with 3.0 mL of dichloromethane. The mixture was dissolved by gently shaking the tube. Once the mixture was completely dissolved, 1.5 mL of 6 M aqueous hydrochloric acid was added to the centrifuge tube. The tube was capped and shaken to thoroughly mix the two phases. The tube was then uncapped and clamped vertically to a ring stand. A pipet was then used to take a sample of the upper layer of the mixture, which was then put into a separate clean centrifuge tube. An equal amount of water was then put into this test tube to confirm that the upper layer was the aqueous layer. The contents in the second tube were then transferred back into the original tube using the pipet.

The lower layer of the mixture, the dichloromethane layer, was then transferred using the pipet into a clean centrifuge tube. The remaining aqueous layer was transferred using the pipet into a separate clean tube labeled “aqueous acid extracts”. The dichloromethane layer was then transferred back to the original centrifuge tube again using the pipet. Another 1.5 mL of 6 M aqueous hydrochloric acid was added to the tube with dichloromethane and the process of separating the two layers was performed for a second time. The aqueous layer was transferred to the same test tube as before containing aqueous acid extracts.

Next, 1.5 mL of cold 3 M sodium hydroxide solution was added to the centrifuge tube containing dichloromethane. The tube was capped and shaken to thoroughly mix the two phases, just as before. The dichloromethane layer was again separated from the aqueous layer, and this time the aqueous solution was transferred into a clean centrifuge tube labeled “aqueous hydroxide extracts”. This process was repeated a second time by adding an additional 1.5 mL of cold 3 M sodium hydroxide solution to the dichloromethane solution.

After that, about 0.3 g of anhydrous sodium sulfate was added to the left over dichloromethane layer remaining in the centrifuge tube. The tube was shaken allowed to stand with occasional swirling. While the tube was allowed to stand, the tube containing aqueous hydroxide extracts was placed into an ice bath and 12 M aqueous hydrochloric acid was added dropwise to the until the solution turned acidic. A precipitate, benzoic acid, formed which was filtered out via vacuum filtration. The benzoic acid was allowed to air dry for a week. It was then weighed at 0.074 g and its melting point was about 119 ºC.

The tube labeled “aqueous acid extracts” was also placed in an ice bath and 6 M aqueous sodium hydroxide was added to the solution until the solution turned basic. A precipitate, p-nitroaniline, formed which was also filtered via vacuum filtration. The p-nitroaniline was allowed to air dry for a week. The resulting p-nitroaniline was weighed at 0.040 g and its melting point was about 139 ºC. The dichloromethane solution which was allowed to stand was decanted into a clean test tube. The solvent was then removed under a stream of nitrogen in the hood. The solid residue, naphthalene, was allowed to air dry for a week. The naphthalene was weighed at 0.035 g and its melting point was 76 ºC.

III. Conclusions

The compounds extracted seem to be slightly impure. The melting points for benzoic acid, p-nitroaniline, and naphthalene that were found are all slightly lower than the melting points I looked up beforehand. There are not huge discrepancies in the numbers, so this leads me to believe the compounds extracted are the expected compounds, they are just not completely pure, which is to be expected.

Error in this experiment could have come from a few different sources. One step that could have led to error was during separation. It was hard to extract only the dichloromethane layer, so I am sure some of the aqueous layer was picked up with it. This means that the resulting aqueous solution, whether it be acid or hydroxide extracts, would yield slightly less benzoic acid and p-nitroaniline than expected. If the error were to happen the other way around and some of the dichloromethane layer was picked up with the aqueous extracts, which means less naphthalene would have resulted than expected. It was impossible to be precise with the separation, so that means there was going to be error in the final weight either way.

If the 3 M sodium hydroxide added during separation was not cold, I think the benzoic acid would not have been as soluble in the aqueous solution and therefore less benzoic acid would have resulted than expected. A couple other obvious spots where error occurred were during vacuum filtration and decanting of the dichloromethane. Some filtrate could have been lost if it were too close to the edge of the filter paper. During the decanting of dichloromethane, some of the liquid may not have made it would of the tube. Lastly, I know it was hard to get all of the naphthalene out of tube to weigh it, so the weight of naphthalene recovered is low.