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Purpose: The purpose of this lab is to remove water from a reaction mixture to form an ester. As water
is removed, the equilibrium is upset. The ester that is being prepared in this experiment is n-propyl
propionate.

Experimental Procedure:
The C structural Formulas for Alcohol and carboxylic acid were drawn out.  Using
densities, the proper amounts of carboxylic acid and alcohol were determined. The proper amounts of
0.974 mL of propanoic acid and 0.823 mL of 1-propanol were determined to be used for the experiment.
The volume of the propanoic acid and 1-propanol were measured and placed into a 5 mL round-
bottomed flask. 2 drops of sulfuric acid were added, while swirling. Then, for heating boiling chips were added. A distillation apparatus was set up which involved a distillation column, condenser, and side-arm. The flask was heated to a gentle boil, then refluxed for 15 minutes.
After 15 minutes to cool the contents, the round-bottomed flask was raised from reflux. The apparatus was also
allowed to cool briefly and the apparatus was then tilted allowing the water and other distillate to drain back
into the round-bottomed flask. Density causes the water to seperate from the distilate and stay in the side arm when tilted. Before being refluxed again, the distillate was drained back into the round-bottomed flask, while the water stay in the side-arm. The round-bottomed flask was lowered back into the sand bath and allowed to reflux for an additional 15
minutes.
 

IFICANCE:  

    The findings of this study will be beneficial for multiple reasons. The data we collect will give us insight into the behavior and lives of the small cellar spiders that live in basements and homes right alongside humans. Today and going forward, LEDs are the new light bulb, they are more efficient, cheaper and easier to install and use. This means that the LED light will began to have a much larger presence in the outdoors as street lamps, lights in the park, etc.. With LEDs becoming more and more prominent and mixed into our surroundings, this study will show some of the effects LED lights can have on spiders creating their webs, eating, sleeping, and just their overall behavior. Comparing the results of this study to studies about regular light bulbs effects on spiders can be very useful  in helping decide where to put LEDs up, how intense to have them, and the schedule for the LEDs. Many people also face fears of spiders, both rational and irrational. Cellar spiders are one of the most common species of spiders to reside in homes and buildings. The results of this study could be helpful for people to repel spiders from making webs in their homes and other places. Depending on the results of this study, potentially, differences in color, brightness, and/or the duration of LEDs could be used by anyone who wants keep spiders away.

Figure 1 and 2 show the elephant seals production of offspring, female and male respectively. FIgure one which sepicts the female seal shows that they have a weak sexual selection. In figure 2 you can see that only a very little percentage of males produce a lot of offspring, and a little produce some and many produce very little to none. These two figures can show us how the elephant seals sexual selection depends entireley on males and rarely on females at all. The male elephant seal clearly has the strongest sexual selection.  Their ability to reproduce is based solely off of size and strength that is put in competition with one another during fights for the area that contains many fertile females. Figures 3 and 4 are similar to figure 2 in that it shows a gap from offspring around 10-15 off spring to around 35-40 offspring.  This is in both the vole figures and shows that not just one gender of the animal has all the strength in sexual selection but it is more base on each gender having better genes or being stronger or something, instead of elephant seals which have just the male fight over the females. In the vole species both genders compete for reproduction. This means that the best of the best from each gender mate with the best of the best and they produce a lot of offspring while the rest of the population does not produce or rarely does.

A:

Figure 1 and 2 show the elephant seals production of offspring, female and male respectively.  The female seal( figure one) has a weak sexual selection and for this species it depends more on the male than female.  In figure 2 you can see that only very little males produce a lot and a little produce some and many produce very little to none.  Compared to the voles the male elephant seal has pretty similar data patterns to figures 3 and 4. The male elephant seal clearly has the strongest sexual selection.  Their ability to reproduce is based solely off of size and strength that is put in competition with one another during fights for the area that contains many fertile females. Figures 3 and 4 are similar to figure 2 in that it shows a gap from offspring around 10-15 off spring to around 35-40 offspring.  This is in both the vole figures and shows that not just one gender of the animal has all the strength in sexual selection but it is more base on each gender having better genes or being stronger or something, instead of elephant seals which have just the male fight over the females. In the vole species both genders compete for reproduction.

B:

OSR is defined as the ratio of sexually competing males to sexually competing females.  For elephant seals the OSR will definitely be above one as we discussed only males compete for sexual reproduction in the elephant seal species.  So there are more males than females competing meaning it must be greater than 1. For the vole species the OSR is harder to predict but should be less than one or equal to one.  This is because a relatively similar number of males and females compete for sexual reproduction in the vole species according to the data in figure 3 and 4. If not more females competing for sex in the species but it looks pretty close so it should be 1 or a little less than 1.

A gentle stream of air was passed over the solution, using the air flow hose in the fume hood, in the 25 mL Erlenmeyer flask to allow the liquid to evaporate. The flask was warmed with a hand until all of the solvent evaporated, and yellow solid remained. The solution was set to dry for 5 minutes.

During recrystallization, 1 mL of acetone was added for every 50 mg of yellow solid. The solution was allowed to cool to room temperature, then the solution was placed in an ice-water bath for an additional 15 minutes. The solution was filtered via vacuum filtration and the crystals were collected on a small Hirsch funnel. The funnel was lifted slightly to cover the crystals with 1 mL of ice-cold acetone, and the filter was placed back down to further vacuum filtration. Air was allowed to pass over the crystals for a few minutes and they were then scraped onto a tared piece of paper. The crystals were allowed to dry to a constant weight.  A small sample was saved to dry further and obtain a melting point.

During hydrolysis, 60 mg of the yellow solid, which is now identified as trimyristin, was weighed and transferred to a clean RB flask using a funnel. 2 mL of 6 M sodium hydroxide, 2 mL of 95% ethanol, and a few boiling chips were added and the solution was refluxed for 45 minutes on sand bath. The rest of the trimyristin was recrystallized a second time while the solution refluxed; allowing the solution to cool to room temperature for 10 minutes before cooling in the ice bath. A minimum amount of acetone was used to dissolve the crystals at the boiling point of the solution. The product was collected using vacuum filtration, and allowed to dry to a constant weight. The melting points of the once recrystallized solid and twice recrystallized solid were compared.

After hydrolysis, the flask was allowed to cool to room temperature. The contents were then poured into a 50 mL beaker containing 8 mL of water. Drop wise, 2 mL of hydrochloric acid were added as the solution was constantly stirred. The solution was filtered and the funnel was lifted 3 times to add very small portions of water (just enough to submerge all of the recovered crystals). The solid was allowed to dry overnight, and a melting point and % yield was taken.

Results:

Starting nutmeg mass: 1 g

Starting material(trimyristin): 0.473 g

After first recrystallization: 0.131 g  MP: 53-54 ℃

After second recrystallization: 0.80 g  MP: 54 ℃

Myristic acid mass:  0.046 g MP: 52-54 ℃

Myristic acid yield: 76.8%

Discussion:

The starting material nutmeg underwent multiple reactions in this lab and the final yield was calculated to be 76.8%.  This is the yield of Myristic acid from 60 mg of starting material after undergoing hydrolysis. Initially 1 g of nutmeg was started with to make .473 g of trimyristin, then a recrystallization was done and 0.131 g were recovered and the product had a melting point of 53-54 ℃.. The product of the second recrystallization had a mass of 0.080 g and had a melting point of 54 ℃. The MP were below the theoretical MP of trimyristin, which means the trimyristin created in this lab contained some impurities decreasing the melting point. Also the range of the MP is important, the higher MP range means the presence of more impurities. The myristic acid from hydrolysis had a mass of 0.046 g which is a percent yield of 76.8 %.  The melting point of the myristic acid was 53-54 ℃, which is very close to actual melting point which is 54.4 ℃. This means the myristic acid was very pure and was easily identified as myristic acid. The yield of the myristic acid and the trimyristin could have been decreased or affected by human error such as letting the mixture boil over and spilling. Other human errors may have contributed to lack of precision and overall error.

Post-Lab Questions

1. A saturated fatty acid is one where hydrogen atoms are attached at all maximum possible locations.  This means that each carbon to carbon bond is a single bond. A fatty with one double bond is a monosaturated fatty acid; a polysaturated fatty acid is one in which there is more than one double bond.  Trimyristin is all single carbon to carbon bonds, which would make it a saturated fatty acid.

2.  The old procedure differs from the new procedure in the fact that a lot of the ether soluble components in the nutmeg will remain in the acetone solution.  If the solution is cooled to room temperature before being put into the ice bath, they ether soluble components would be allowed to dissolve further before being put into the ice bath.

3. (1.8 g of tristearin)*(1 mol tristearin/891.48 g tristearin)*(3 mol stearic acid/1 mol tristearin)*(284.48 g stearic acid/1 mol stearic acid) = 1.723 g stearic acid

4. The mixture is a high boiling mixture.  The mixture needs to be refluxed. Reflux occurs when a mixture is heated at a high temperature for a certain amount of time, which allows vapor to be produced and cooled in a condenser dripping back into the round-bottomed flask.  This allows for a high separation.

5. If the mixture were heated at that temperature for 45 minutes, there would not be as high of a separation achieved from the reflux.  Heat speeds up a chemical reaction, if the solution were allowed to reflux at that temperature for a longer period of time, then the solution may achieve the chemical reaction that is wanted.

TA – Manisha

Tuesday, 8 AM

Submitted: Oct, 30 2018

Isolation of Trimyristin from Nutmeg

Purpose:

The purpose of this experiment is to obtain a pure organic compound, trimyristin, from the natural source nutmeg. The techniques of extraction, distillation, recrystallization, and chromatography are used to isolate and purify the chemical compounds from the natural sources.

Reaction:

Trimyristin                                Myristic Acid:

MP: 56-57  ℃                                MP: 54.4 ℃

MW: 723.16 g/mol                             MW: 228.37 g/mol

Experimental Procedure:

1.0 g of nutmeg was weighed out on a scale and transferred into a round-bottomed flask using a funnel. 3 mL of tert-butyl methyl ether and 3 boiling chips were also added to the RB flask. A distillations column and air condenser were set up with the black plastic connector to yield the highest results. The flask was lowered into the sand and monitored at a very gentle boil. The mixture was heated for 10 minutes, and then allowed to settle for a few minutes. The color of the mixture changed slightly to a lighter brown. Using a pipet, as much as of the liquid as possible was transferred to a test tube to settle further. The solids were left behind in the RB flask. The liquid was allowed to settle for a few minutes for even further separation of liquid ad small remaining solids. An empty 25 mL flask was pre-weighed. The liquid was transferred via pipet from the test tube to the clean 25 mL Erlenmeyer flask.

Filtration was performed by packing a glass pipet with a plug of cotton; the solution in the 25 mL Erlenmeyer flask was transferred via pipet and filtered through the cotton filter. The solution was allowed to drain completely before a new addition was performed. A pipet bulb was used to help speed up filtration. All of the solution from the Erlenmeyer flask was transferred.

2 mL of fresh tert-butyl methyl ethyl was added to the solid in the RB flaks and warmed very briefly to allow the solids to settle and the liquid was then transferred via pipet into the test tube and allowed to settle further. The liquid was then transferred from the test tube through the cotton pipet filter using a piper and into the same 25 mL Erlenmeyer flask as before.

The excel sheet should include the distance(in cm) of the spider from the LED light (in the x,y,and z dimension), and the diameter of the web, if present at all. This will be recorded with a ruler from outside the container.  Pictures of the spider best depicting its distance from the LED can be taken for reference. Determine whether the light, time exposure, length, color, brightness, or species of spider had any effect on presence of webs in the chamber. This is done by comparing each project results to one another and deciding whether the web that was produced was influenced by the light that was exposed to the spider. If the spider was attracted to the light, then the distance of the web from the light should be smaller than if the spider was not attracted to the web.

SIGNIFICANCE  

    The findings of this study will be very beneficial for multiple reasons. The data we collect will give us insight into the behavior and lives of the small cellar spiders that live in basements and homes right alongside humans. Today and going forward, LED lights are the new light bulb, they are more efficient, cheaper and easier to install and use.

Putting up a finished project onto a poster board to present has been a part of science forever. Some things constitute a good poster while others bad, and some combination land most posters in between. A scientific poster can be viewed as good to different people for different reasons, like the opinion of the article or the subject matter being discussed. These are important but also some things across the board that make a good poster.  Such as, the title must sum up the experiment is an understandable way. The bear minimum requirement for the title should be that, but a good title will also intrigue the reader and almost trap them into wanting to read the rest. The title “ Using zebrafish larval models to study brain injury, locomotor and neuroinflammatory outcomes following intracerebral haemorrhage [version 2; referees: 1 approved, 1 approved with reservations]” is a basic title, just getting the point across, barely simplifying it. Compared to this title, “Are we aiming to miss in translational autoimmunity treatments?[version 1; referees: awaiting peer review]”, which involves the reader and tries to grab their interest with a question.  Another important aspect of a poster is the display of the data, if it is hard to see or make sense out of, the reader is more inclined to lose interest. Having the entire project be displayed in such a manner that someone who has no clue on the subject can generally figure it out is the aim. This means using words that are not unique to the field of study or if used explaining them in everyday terms. Another good key for quality posters is length, if the poster is too long it can scare readers away and if too short make them not see the point in the project. Many good things contribute to the quality of posters, these are just a few.

Figure 1: This is the basic setup for the LED during this study. Multiple resistors and multiple different colors will be used.

Putting up a finished project onto a poster board to present has been a part of science forever now and some things constitute a good poster while others bad, and some combination can land most posters in between.  A scientific poster can be viewed as good to different people for different reasons, like the opinion of the article or if that's a field the reader is genuinely into. These are important but also some things across the board that make a good poster board are things such as, the title must sum up the experiment is an understandable way.  The bear minimum requirement for the title should be that, but a good title will also intrigue the reader and almost trap them into wanting to read the rest. The title “ Using zebrafish larval models to study brain injury, locomotor and neuroinflammatory outcomes following intracerebral haemorrhage [version 2; referees: 1 approved, 1 approved with reservations]” is a basic title, just getting the point across, barely simplifying it.  Compared to this title,

“Are we aiming to miss in translational autoimmunity treatments?[version 1; referees: awaiting peer review]” which involves the reader and tries to grab their interest with a question.   Another important aspect of a poster is the display of the data, if it is hard to see or make sense out of, the reader is more inclined to lose interest.  Having the entire project be displayed in such a manner that someone who has no clue on the subject can generally figure it out is the aim. This means using words that are not unique to the field of study or if used explaining them in everyday terms.  Another good key for quality posters is length, if the poster is too long it can scare readers away and if too short make them not see the point in the project. Many good things contribute to the quality of posters, these are just a few.