1

Fischer Esterification and Identification

of Butyl Acetate

Johan Villanueva

Lab Partner: Daniel Shipchandler

TA: Matthew Pearson

April 30th, 2018

5.310 MW

Abstract

The reaction of acetic acid and 1-Butanol with sulfuric acid created butyl acetate.

Methods of refluxing, separation, and atmospheric distillation yielded 14.8363 ± 0.0012 grams of

purified butyl acetate with a percent yield of 38.95%. The smell of banana Laffy Taffy, density

of 0.874 g/mL, boiling point of 125.4˚C, refractive index of 1.3940, and spectrums of IR, NMR,

and mass spectroscopy accurately characterization the molecule to be butyl acetate when

compared to the literature values.

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Introduction

Esters are created by the condensation of an alcohol with a carboxylic acid (Known as

Fischer Esterification) through a rapid forward/reverse reaction. Found in fruits, vegetables,

paints, perfumes, and cosmetics, esters are compounds with unique fragrances. Acid catalysts are

added to induce the production of more products while water is removed to isolate and

specifically have only the ester be produced. While unknown at the time, this experiment follows

the creation of the ester butyl acetate. Formed by the carboxylic acid, acetic acid, and alcohol, 1-

Butanol, this ester underwent several chemistry techniques to yield the most amount of product,

remove any impurities, and obtain as much information to be able to characterize it. Figure 1

shows the reaction scheme of this experiment.

Refluxing was the first process performed intended to synthesize the ester. It vaporized

the liquid, allowed the reaction to occur, and then condensed back into a liquid with the coolant

water flowing around it. To remove acid impurities, a separatory funnel along with a base

solution was mixed with the condensed product. To remove water, sodium chloride and an

anhydrous chemical agent were introduced. To remove any remaining purities, the ester

underwent atmospheric distillation. At this point, the ester has been purified to the best of the

available techniques. In addition, an aroma would come from the vial, with this compound

having a banana-like Laffy Taffy smell.

Before characterization, the thermometer was calibrated by checking the freezing and

boiling points to ensure accuracy. Afterwards, the boiling point of the ester was taken. By

heating at a constant temperature until the molecule vaporizes and the temperature readings on

the thermometer stop changing, it provided the boiling point. Another characterization method

was finding the density. Since density is mass over volume, all it take is measuring both values at

the same time. Using a graduate burette and a scale, one could choose how much volume to

relieve while measuring the new mass value. Repeat for several trials and one can get the density

after plotting. Both these data points gave clues to finding the identity of the unknown ester.

Figure 1. Reaction of acetic acid and 1-butanol to form butyl acetate

and water. Appendix Figure 10 shows detailed mechanism.

3

A refractive index was taken by adding a sample of the unknown ester to the

refractometer. It works by measuring refracted light when going through the molecule, therefore,

determining the refractive index. In addition, an infrared spectroscopy was done on the ester.

This machine provides data to identify any functional groups in the molecule. By adding a

sample of the ester on an IR card, the machine measures vibrations as it is exposed to infrared

light. Both data values when compared to literature values all serve to learn more about the

unknown molecule.

Proton nuclear magnetic resonance (NMR) determines the structure. By inserting a vial

containing the ester into the NMR machine, a magnetic field will then spin the nuclei, which in

turn provides different results on the spectrum. The energy differences is what plotted as it

returns to lower energy levels. After running through a math program, radio frequency levels

inside allow to see the differences in the spectrum. With the electron surrounding the nuclei, this

induces a current, provides a magnetic field, and a field less than the applied magnetic field is

created. For each nuclei, they will have different values and overall, the spectrum obtain has

identified the structure of the ester without breaking the molecule. With mass spectrometry,

which allows understanding the weight of the molecule, it breaks off segments of the molecules

using high-energy electrons while varying the magnetic field. They will create radicals and often

involved itself in subsequent reactions, with only the positive ones reaching the detector.

Comparing the different values and the number of times the fragment piece was found, it can be

identified the weight of the fragments and all together, find out the weight of the molecule.

Overall, the goal of this experiment is to characterize after synthesizing an ester with

unknown reactants. It will require the practice of multiple chemistry techniques and intuition to

identifying the compound. It significant because once the results are found, it will verify whether

one is qualified in completing these chemistry procedures. In addition, it exposes one to many

methods of identification that allows one to be well informed for the future.

Procedure and Observations

Previously weighed by the TA, obtained 40.0 mL of unknown carboxylic acid and 30.0

mL of unknown alcohol (Both clear samples; Number 17 samples). Worked under a fume hood.

Using a funnel, added unknown carboxylic acid, unknown alcohol, and 3 mL of sulfuric acid

[H2SO4] to a 250 mL round bottom flask [RBF]. Set up reflux apparatus as seen in appendix

Figure 2. Added stir bar to RBF, greased before connecting glassware, and attached clamps

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throughout the apparatus. Connected heating mantle to rheostat. Turned on stirrer. Set rheostat to

75 electrical units and left for an hour to reflux after boiling started. Meanwhile, set up a

separatory funnel at the lab desk as seen in appendix Figure 3. After reflux completed, allowed to

cool to room temperature. Transferred contents of reflux to the separatory funnel (Banana-like

Laffy Taffy smell). Added 60 ± 0.1 mL of cool distilled water to separatory funnel. Used 20 ±

0.1 mL of cool distilled water to rinse out the RBF and added it to the separatory funnel. Swirled

and allowed layers to separate. Removed aqueous layer. Moved organic layer to beaker, added

5% sodium bicarbonate [NaHCO3] solution, transferred to separatory funnel, covered with

stopper after settling, shook, inverted, released pressure, inverted, removed stopper, allowed

layers to separate, discarded NaHCO3, and repeated entire process until used 660 mL of

NaHCO3. Checked with litmus paper until signs of basic (Color blue). Repeated previous sets

regarding NaHCO3, instead now using 20 ± 0.1 mL of saturated aqueous sodium chloride [NaCl]

solution. Once NaCl removed, added 4 grams of magnesium sulfate [MgSO4]. Swirled and

transferred only the organic layer using a glass pipet to as many necessary vials.

Measured and marked four vials without caps. Worked under a fume hood. Using a

funnel and filter paper, filled RBF with contents from collected vials. Set up atmospheric

distillation apparatus hood as seen in appendix Figure 4. Added a stir bar to RBF, greased before

connecting glassware, and attached clamps throughout the apparatus. Connected heating mantle

to rheostat. Turned on stirrer. Began distillation by setting rheostat to 40 electrical units and

wrapping apparatus with tinfoil. As seen on Table 1, constantly adjusted electrical units to have a

continuously single drop rate per 2-3 seconds. Changed vials after 17 drops (Vial 1 to 2), after

temperature started to lower (Vial 2 to 3), and after temperature raised (Vial 3 to 4). Stopped

distillation after about 2 mL remained in the RBF. Allowed to cool to room temperature.

Measured vials containing the products without caps.

Calibrated digital thermometer by taking freezing and boiling points. Set up a 150 mL

beaker filled with ice and distilled water; took temperature after freezing for 15 minutes. Set up a

150 mL beaker filled ¾ with distilled water and covered with alumni foil; took temperature after

boiling for 20 minutes. Used calibrated thermometer to obtain boiling point of unknown ester.

Transferred 0.3 mL of unknown ester into a test tube. Placed test tube into a boiling point

apparatus out in the lab as seen in appendix Figure 5. Obtained boiling point by allowing to heat

up until temperature stopped rising.

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Transferred 50 ± 0.01 µL of unknown ester from vial 2 and 900 µL of deuterated

chloroform into a 5 mm NMR tube using a glass pipet. Capped and then inverted multiple times.

Placed NMR tube into sample warmer. Placed NMR tube in 60 MHz NMR machine, performed

scan with help from the TAs, and collected spectrum.

Added drops of unknown ester from vial 2 on an IR card, inserted into the cardholder,

and scanned using the setup provided by the TAs. Cleaned refractometer using methanol, then

wiped, then added water, then wiped again. Took refractory and temperature readings of water

and unknown ester.

Filled 10 ml of the graduated burette with unknown ester. Set up using a Sartorius

balance, vial, and graduated burette as seen in appendix Figure 6. Dripped varying amounts and

recorded each time the change in mass. Covered the balance before recording to ensure accuracy.

Added 3 drops of unknown ester to 1.00 ± 0.01 mL of pentane in a vial. Transferred 0.10

µL of mixture with a sterile needle into a mass spectrometry apparatus. Took fragmentation

readings.

Results and Calculations

Table 1: General reaction information

Molecule Density

(g/mL)

Molecular

Weight

(g/Mol)

Volume

(mL) Mass (g)

Amount

(Mols)

Acetic Acid 1.05 60.05 40.0 42.0 0.699

1-Butanol 0.81 74.12 30.0 24.3 0.328

Butyl Acetate

(Theoretical Yield) 0.883 116.16 43.3 38.1 0.328

𝑀𝑎𝑠𝑠 = 𝐷𝑒𝑛𝑠𝑖𝑡𝑦 × 𝑉𝑜𝑙𝑢𝑚𝑒 =1.05 𝑔

1.00 𝑚𝐿× 40.00 𝑚𝐿 = 42.00 𝑔

𝐴𝑚𝑜𝑢𝑛𝑡 = 𝑀𝑎𝑠𝑠 ×1

𝑀𝑜𝑙𝑒𝑐𝑢𝑙𝑎𝑟 𝑊𝑒𝑖𝑔ℎ𝑡= 42.00 𝑔 ×

1 𝑚𝑜𝑙𝑠

60.05 𝑔= 0.699 𝑀𝑜𝑙𝑠

𝑇ℎ𝑒𝑜𝑟𝑒𝑡𝑖𝑐𝑎𝑙 𝑌𝑖𝑒𝑙𝑑 = 𝑀𝑜𝑙𝑒𝑠 𝑜𝑓 𝐿𝑖𝑚𝑖𝑡𝑛𝑔 𝑅𝑒𝑎𝑐𝑡𝑎𝑛𝑡 × 𝑅𝑎𝑡𝑖𝑜 𝑜𝑓 𝑀𝑜𝑙𝑒𝑠 × 𝑀𝑜𝑙𝑒𝑐𝑢𝑙𝑎𝑟 𝑊𝑒𝑖𝑔ℎ𝑡

= 0.328 𝑀𝑜𝑙 1 − 𝐵𝑢𝑡𝑎𝑛𝑜𝑙 ×1 𝑀𝑜𝑙 𝐵𝑢𝑡𝑦𝑙 𝐴𝑐𝑒𝑡𝑎𝑡𝑒

1 𝑀𝑜𝑙 1−𝐵𝑢𝑡𝑎𝑛𝑜𝑙×

116.16 𝑔 𝐵𝑢𝑡𝑦𝑙 𝐴𝑐𝑒𝑡𝑎𝑡𝑒

1 𝑀𝑜𝑙 𝐵𝑢𝑡𝑦𝑙 𝐴𝑐𝑒𝑡𝑎𝑡𝑒= 38.1 𝑔

Table 2: Vials before and after collecting from the distillation

Vials Before Distillation (g) After distillation (g)

1 12.8151 ± 0.0005 13.0227 ± 0.0005

2 12.7827± 0.0005 23.1001 ± 0.0005

3 12.7388 ± 0.0005 14.2773 ± 0.0005

4 12.8287 ± 0.0005 15.8091 ± 0.0005

Ester collected (g) 14.8363 ± 0.0012

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𝑃𝑒𝑟𝑐𝑒𝑛𝑡 𝑌𝑖𝑒𝑙𝑑 = 𝐴𝑐𝑡𝑢𝑎𝑙 𝑌𝑖𝑒𝑙𝑑

𝑇ℎ𝑒𝑜𝑟𝑡𝑖𝑐𝑎𝑙 𝑌𝑖𝑒𝑙𝑑× 100% =

14.84 𝑔

38.1 𝑔× 100% = 38.95%

Using thermometer-calibration curve equation from appendix Figure 8 and Table 8:

𝑇ℎ𝑒𝑜𝑟𝑒𝑡𝑖𝑐𝑎𝑙 𝑇𝑒𝑚𝑝𝑒𝑟𝑎𝑡𝑢𝑟𝑒 = 𝑂𝑏𝑠𝑒𝑟𝑣𝑒𝑑 𝑇𝑒𝑚𝑝𝑒𝑟𝑎𝑡𝑢𝑟𝑒 − 1

1.0054

𝐵𝑜𝑖𝑙𝑖𝑛𝑔 𝑃𝑜𝑖𝑛𝑡 𝑜𝑓 𝐸𝑠𝑡𝑒𝑟 =127.1 − 1

1.0054= 125.4˚𝐶

Using excel and density curve from appendix Figure 9 and Table 9:

𝜌 = 0.874𝑔

𝑚𝐿

𝑆𝑡𝑎𝑛𝑑𝑎𝑟𝑑 𝐷𝑒𝑣𝑖𝑎𝑡𝑖𝑜𝑛 = 𝑆𝑒𝑚 × √𝑁 = 0.010264 × √6 = 0.02514

95% 𝐶𝑜𝑛𝑓𝑖𝑑𝑒𝑛𝑐𝑒 𝐿𝑖𝑚𝑖𝑡𝑠 = 𝜌 ± 𝑡 × 𝑆𝑒𝑚 = 0.874 ± 2.45 × 0.01026 = (0.849,0.899)

Table 3: Data collected from refractometer

Data Type Literature Value Recorded Value Calibrated Value Temperature

Value (˚C)

Refractory Index of Water 1.3329 1.3323 1.3363 27.6

Refractory Index of Ester 1.3941 1.3905 1.3940 27.7

∆𝑛 = 4.5 × 10−4(𝑇𝑅𝑒𝑓𝑟𝑎𝑐𝑡𝑜𝑚𝑒𝑡𝑒𝑟 − 𝑇𝐷𝑒𝑠𝑖𝑟𝑒𝑑) = 4.5 × 10−4(27.7 − 20.0) = 0.0035

𝑛𝐷20 = 𝑛𝐷

27.7 + ∆𝑛 = 1.3905 + 0.0035 = 1.3940

Figure 7. NMR segments of butyl acetate.

Table 4: NMR tabulated from appendix spectrum.

Carbon Section Measured Peaks (ppm) Number of Actual Hydrogens

A 3.80 - 4.30 3

B 1.90 - 2.10 2

C 0.60 – 1.75 7

Table 5: IR tabulated from appendix spectrum and Figure 11.

Function Group Range Wavelength (cm-1) Actual Wavelength (cm-1)

C-O-C 1050-1250 1240.18

CH3 1440-1465 1462.64 , 1472.91

C=O 1720-1750 1763.64

C-H 2840-2950 2850.14 , 2915.49

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Table 6: Mass spectroscopy tabulated from appendix spectrum.

M/Z Possible Fragment Abundance

15.10 •CH3 616

28.15 CO2• 34901

29.10 CH2O• or •C2H5 7383

43.10 •C3H7 or C2H3O• or Acylium 61856

57.15 •C4H9 7843

73.10 C4H9O• or •C3H5O2 5417

Discussion

In identifying the unknown ester, it starts with the use of the reflux apparatus from

appendix Figure 2. First, the reactants went into the round bottom flask [RBF] using a funnel to

avoid any of it remaining on the mouth of the flask. The RBF had to contain the two unknown

solutions of carboxylic acid and alcohol with drops of the catalytic acid, sulfuric acid [H2SO4].

This acid would induce a greater production of the product due to providing more hydrogen [H+]

molecules. Looking at the reaction mechanism on appendix Figure 10, the reaction starts with the

attachment of H+. With it being catalytic, it means these hydrogens are not consumed and

therefore having more of them will help react as much as there is available. The reflux apparatus

was lubricated with grease before attaching in order to seal well and keep the gases from

escaping. Water ran surrounding the condenser for once the vaporize molecules reacted, it would

drip back down as a liquid. A drying tube was attached at the top to remove any vaporized water.

The whole purpose of the reflux is to first create the products, but decreasing the amount of

impurities or water from the starts makes it easier for later. Especially the removal of water helps

by promoting the production of butyl acetate because of Le Chatelier’s principle where the

removal of a one of the products increases the productions of the other products for the same

reaction. From Figure 1, it shows that butyl acetate and water are the two products; therefore,

removing water is necessary for increase yield.

After refluxing, the contents of the RBF were transferred to a beaker. Distilled water that

had washed out the used instruments from the reflux apparatus was then transferred to the same

beaker to maximize the amount of product. Adding water is not an issue because future steps can

easily remove water from the contents. First, it was time to get rid of impurities. To remove

impurities, the acidic product was mixed with sodium bicarbonate that removed both the H2SO4

and carboxylic acid, overall neutralizing the product. This would create carbon dioxide, but since

it was exposed to the air in a beaker it was not an issue. A separatory funnel was used as from

8

appendix Figure 3, where the contents of the beaker were transferred in there and inverted

multiple times in order to get the base to neutralized. However, this built pressure from the

bubbles, which was carbon dioxide, but was handled by turning the stopcock until it released

pressure and stopped making noise, therefore, indicated a lower pressure. Once no more bubbles

would form, the separatory funnel was left on the ring stand to separate the layers. While settling

on the stand, the glass stopper was removed to avoid the pressure buildup; otherwise, the stopper

would have been stuck. Once the organic layer and aqueous solutions were separated, the

aqueous solution was discarded and the process was repeated until the organic layer reached the

blue part of the litmus paper, indicating acid had been neutralized. To remove water, two steps

were taken. Sodium chloride and magnesium sulfate were introduced to remove any remaining

water. Then, the unknown ester was transferred to vials for safekeeping.

Afterwards, the products went through atmospheric distillation. Once again, it would

remove any remaining reactants and water. Before introduced to another RBF, another funnel

now with a filter was used to make sure none of the magnesium sulfate would fall in the RBF. As

seen in appendix Figure 4 and Table 7, heat was constantly adjusted, product was condensed, and

the contents were set-up to fall in specific vials for the atmospheric distillation apparatus. The

whole apparatus was greased before connecting to ensure the vaporized liquids remained until it

turn back into a liquid at the condenser portion. Appendix Table 7 further reflects the actual

timing when distillation was performed and specifically at which points vials were used. The

vials would be switched when there was a great change in temperature. While vial 2-4 contained

the product, vial 1 contained any impurities and was discarded. Once the temperature reach

extremely high values, it indicated that the ester product was being collected. Tin foil was used

to keep the apparatus warmer and not lose heat due to its surroundings. This ensures a proper

vaporization. Distillation was stopped once about 2 ml remained in the flask to avoid higher

boiling point impurities.

Looking at Table 1, the information illustrates the theoretical yield for the reaction. 1-

Butanol turns out to be the limiting reactant, as the ratios are all 1:1 according to reaction scheme

from Figure 1 and because it is the reactant with less moles. Following calculations, the expected

yield is 38.1 g of butyl acetate. Table 2 tabulates the before and after collection of the vials from

the distillation portion. Overall, 14.8363 ± 0.0012 g was collected from vials 2-4, however, the

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percent yield disappointingly calculated to be 38.95%. However, what was collected is used for

identifying the ester.

Different methods of characterization were necessary in order to obtain as much

information. This allows for various comparisons with literature values that can help accurately

identify the unknown ester molecule. Before using all the machines, the smell of the product was

the first bit of information obtained about the ester. It fumed a banana-like Laffy Taffy smell.

With this information, it certainly reduced the possible esters to less than four. However, it was

not enough and more data was needed. Knowing it was butyl acetate, this description is slightly

accurate except for the mention of it also being an apple smell from the references in the manual.

While an apple smell was unrecognized, the banana smell was indeed present.

The boiling point was taken as seen in Figure 5. What was extremely difficult was getting

the temperature readings to go above 60. While working under a fume hood, the air did not allow

the boiling point temperature to increase. It was unbelievable to be a low temperature due to the

atmospheric distillation needing close to 120˚C to distill. It had to be perform out in the lab, no

matter the toxins, because it was necessary to complete this characterization. Figure 8 indicated

the calibration curve and Table 8 represents the data collected to calibrate the thermometer. It

was necessary to calibrate because clearly it was inaccurate in its reading by about 1˚C. With

obtaining the equation from the curve and rearranging it, the boiling point of the ester was

125.4˚C. Compared to the actual one being 126.1˚C from Table 8, it reflects a characterization

method performed accurately and precisely. The differences are not too far apart to not be

confident in the results.

Density was determined with the setup from Figure 6. While a simple idea of measuring

out the volume and recording the mass, intentionally different volumes were chosen to obtain

different masses to see if the density was accurate. After obtaining the data that is seen on Table

9, Figure 9 can be obtained through using Excel’s tools and information including the Sem and N.

The slope of the graph on Figure 9, representing density, was found to be 0.874 g/mL. If

comparing to the literature value from Table 1, being 0.883 g/mL, the values are close but could

have been better. There was an issue realized afterward of how incorrect the readings recorded

were on the graduated cylinder. This skewed the results and definitely induced some outliers.

Not all, but a couple of the results were likely inaccurately recorded.

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Refractometry was one of the methods conducted. How this works is depending on the

amount of refracted light determines the refractive index value. Temperature was recorded to use

in the correction formula. According to Table 3, once calibrated from the recorded values, it was

determined to be 1.3940. Knowing it was butyl acetate at the time and comparing to the literature

value of 1.3941, this means both accuracy and great purity from the sample. This was a

successful form of characterization.

Protein nuclear magnetic resonance (NMR) gave the name of the structure. NMR takes

an amount of ester and deuterated chloroform, which removes any solvent peaks on the spectrum

and stabilizes the magnetic field. Then, preheated with the sample warmer to increase accuracy.

Once the spectrum was obtained, one had to work backwards and identify the structure and

placement of hydrogen in regards to carbon. While Figure 7 represented the final image from the

NMR spectrum after full analyzation, Table 4 represents the data that gave hints to the

placements of all the hydrogens. First, it was important to get the correct hydrogen values.

Looking at the original spectrum in the appendix, the integration values made the values half

what they actually were. Multiplying by two gave all the integrated value an integer number and

were now correct. Now, it was important to look at the measured peaks placement and compare

to data values from online charts. When identifying where the hydrogen were to be, the number

of peaks per group represented a value that had to be subtracted by one. The new value indicated

the number of other hydrogen near the carbon, excluding its own. During the analyzation, carbon

section A and B were easy and identified most of the molecule. However, because section C was

not well integrated, it was confused the ending of the molecule and left some ambiguity. The

NMR provided half the name and only left the right side ambiguous at the time.

Infrared spectroscopy (IR) data is seen on Table 5. While this was the most useless of all

characterization method, it offered the functional groups after measuring vibrations using

infrared light. It felt redundant and only confirm all the work from the NMR. Falling in the

ranges provided by appendix Figure 11 IR chart, it confirmed the existence of C-O-C by being

1240.18 cm-1, CH3 by being 1462.64 cm-1 and 1472.91 cm-1, and C=O by being 1763.64 cm-1.

While without the NMR, the IR would have gain more importance to this characterization

method, at least IR confirmed the data behind the NMR.

Mass spectrometry was taken; however, this was the last of all methods. At the point of

using this machine, the molecule had already been identified properly. Mass spectrometry only

11

brought more questions than answers. First, this was not the full spectrum. The spectrum only

went to about 73 m/z while the molecular weight is about 116 g/Mol. It is likely the molecule

was not stable enough to be detected. This spectrum did hint at the entire structure. While it was

difficult to identify all the peaks due to not knowing exactly how the electrons broke off the

molecule, several fragments were identified as seen in Table 6. This included •CH3, •CH2O,

•C2H5, •C3H7, •C2H3O, •C4H9, •C4H9O, and •C3H5O2. Seeing all these potential radicals, an

incredible mind could piece together what molecule it would have been comparing the

abundance. Overall, mass spectrometry is useful when it works accurately.

Sources of potential error are plentiful. First, the amount of H2SO4 was 3 ml, but perhaps

more would have been a safer bet. In addition, taking more time to do each process would have

been secured greater yield. Transferring between beakers, apparatuses, and vials can leave some

ester product remaining or accidently spilling. Especially in the reflux and separatory funnel

portion, taking a longer time would have saved any lost product. While transferring to the RBF

before distillation, some spilled while in the funnel with the filter paper because of pouring too

quickly. When doing the distillation, the decision to adjust temperature after finally heating the

actual product was a mistake and would have been better to be left alone. Looking at appendix

Table 7, the dip in temperature was human error and a change in vial was necessary to ensure

purity in the other vials. In addition, error could be in the timing to change vials. The wrong

moment might have been chosen, therefore, missing some product. However, in terms of success

in the goal of the experiment, these sources of error did not stop from identifying the unknown

ester. There was enough product to be used in all machines. When looking across literature

values and calibrated values, the results recorded were accurate. The methods performed can be

said to be done successfully. A better yield would have been perfect.

Additional improvements to this experiment include redoing the mass spectrometry to

fully confirm obtained values and get the accurate mass. In addition, density would be redone

now knowing exactly how to read the graduated cylinder properly. Repeating trials would

increase the precision of the results, however, seeing that the correct molecule was identified,

butyl acetate, from the unknown compounds of 1-butanol and acetic acid, the results indicate the

entire experiment was successful.

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Conclusion

The reaction of carboxylic acid, acetic acid, and alcohol, 1-Butanol, with sulfuric acid

created butyl acetate. Undergo methods of refluxing, separation, and atmospheric distillation

yielded 14.8363 ± 0.0012 grams of purified butyl acetate with a percent yield of 38.95%. To

characterize, methods of smell, density, boiling point, refractive index, IR spectrum, NMR

spectrum, and mass spectroscopy spectrum were used to accurately pinpoint the molecule. While

a better mass spectroscopy could have confirmed the weight, all the data collected identified the

compound to be butyl acetate.

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ational_Spectroscopy/Infrared_Spectroscopy

Infrared Spectroscopy Table. (2001). UCLA. Retrieved from

http://www.chem.ucla.edu/~bacher/General/30BL/IR/ir.html

Refractometry. (n.d.). Online Lab Manuel Home. Retrieved from

http://academics.wellesley.edu/Chemistry/chem211lab/Orgo_Lab_Manual/Appendix/Inst

ruments/Refractometry/refractometry.html

Reusch W. (2013). Nuclear Magnetic Resonance Spectroscopy. Retrieved from

https://www2.chemistry.msu.edu/faculty/reusch/virttxtjml/spectrpy/nmr/nmr1.htm

13

Appendix

1. Stirrer

2. Heating mantle

3. 250 ml round bottom flask

4. 14/20 condenser

5. Inflow water tubing

6. Outflow water tubing

7. Drying tube

Figure 2. Diagramed reflux

apparatus

Figure 3. Separatory

funnel apparatus

1. Beaker

2. Stopcock

3. Separatory funnel

4. Ring stand support

5. Stopper

14

1. Stirrer

2. Heating mantle

3. 250 ml round bottom flask

4. Vigruex column

5. Coupler

6. Thermometer holder

7. Glass thermometer

8. Reflux condenser

9. Outflow water tubing

10. Inflow water tubing

11. Distillation Head

12. Vial inside ice bath

13. Stand Figure 4. Diagramed atmospheric

distillation apparatus

Figure 5. Diagrammed boiling

point apparatus.

Figure 6. Diagrammed

density apparatus. 1. Heating mantle

2. 80x40 Pyrex heating

dish with sand

3. 13x100mm Test tube

4. Digital thermometer

1. Vial

2. Sartorius balance

3. Graduated burette

15

Table 7: Data collected during atmospheric distillation

Electrical Units Time

(Minutes : Seconds)

Temperature

(˚C) Which Vial

40 00:00 22

1

60 01:55 22

70 07:00 22

75 12:00 22

85 17:00 23

85 19:00 99

80 22.30 119

2 70 23.00 119

60 24.00 119

50 24.30 119

50 25:30 119

3 65 26:55 104

75 28:00 85

80 29:12 69

75 33.30 118 4

0 36:00 118

Table 8: Data collected regarding freezing and boiling points

Data Type Literature Value

(˚C)

Recorded

Value (˚C)

Calibrated Value

Freezing Point of Water 0 1 -

Boiling Point of Water 99.66 101.2 -

Boiling Point of Ester 126.1 127.1 125.4

𝑇ℎ𝑒𝑜𝑟𝑒𝑡𝑖𝑐𝑎𝑙 𝐵𝑜𝑖𝑙𝑖𝑛𝑔 𝑃𝑜𝑖𝑛𝑡 𝑐𝑜𝑟𝑟𝑒𝑐𝑡𝑖𝑜𝑛 = (𝐴𝑡𝑚𝑜𝑠𝑝ℎ𝑒𝑟𝑖𝑐 𝑝𝑟𝑒𝑠𝑠𝑢𝑒 − 760 𝑚𝑚 𝐻𝑔) × (0.037°𝐶

𝑚𝑚)

= (750.824 − 760) × 0.037 = −0.339

Table 9: Mass recorded while volume was added

to determine density

Volume Recorded (mL) Mass Recorded (g)

0.60 ± 0.01 0.000

2.20 ± 0.01 1.389 ± 0.001

4.10 ± 0.01 3.085 ± 0.001

5.60 ± 0.01 4.366 ± 0.001

7.00 ± 0.01 5.665 ± 0.001

7.75 ± 0.01 6.320 ± 0.001

8.86 ± 0.01 7.051 ± 0.001

9.50 ± 0.01 7.858 ± 0.001

16

Figure 8: Thermometer calibration curve created by the data from Table 8 with an equation and

R2 value.

Figure 9: Density curve created by the data from Table 9 with an equation and R2 value.

y = 1.0054x + 1R² = 1

0

20

40

60

80

100

120

0 20 40 60 80 100 120

Ob

serv

ed

Val

ue

Theoretical Value

Thermometer Calibration Curve

y = 0.874x - 0.5161R² = 0.9992

0

1

2

3

4

5

6

7

8

9

0 2 4 6 8 10

Mas

s (g

)

Volume (mL)

Density Curve

17

Figure 10. Mechanism for the butyl acetate ester.

Figure 11. Infrared Spectroscopy Table from UCLA