CHEM 233 Final Exam

In an effort to optimize the bromination reaction, you repeat the reaction three times with each attempt using a slightly different set of reaction conditions. The melting points of the crude products of each reaction are shown below. Which reaction produced the most pure crude product ? Reaction 1: 110 - 114 °C Reaction 2: 108 - 114 °C Reaction 3: 113 - 116 °C

Reaction 3: 113 - 116 °C

Which of the following IR stretches would be consistent with the C-H bond in the below structure where the carbon is sp hybridized? (H - C☰C) 3300 cm-1 3100 cm-1 2950 cm-1 2100 cm-1 1700 cm-1

3300 cm-1

Which of the following stretches would NOT be present in an IR spectrum of the below compound? Select all that apply. (terminal alkene, sp3 C, carbonyl) 3400 cm-1, broad 3300 cm-1 3100 cm-1 2950 cm-1 2100 cm-1 1700 cm-1 1650 cm-1

3400 cm-1, broad 3300 cm-1 2100 cm-1 (3000-3100 : sp2 C, 1650 : C=C, 1700 : C=O, 2900-3000 : sp3 C)

How many 20 mL extractions of organic solvent are needed to extract at least 99.5% of 50.0 g Compound A from 100 mL of water if K=10? Remember, extractions can only occur in whole numbers! (2 pt) Hint: Based on the information in the question, what mass of Compound X should be in the aqueous layer? Also, you did review your basic logarithmic rules, yes?

5

Given the partition coefficient between ethyl acetate and water for Compound A is 7.0, what mass of A, to the tenths place, would be extracted from a 50 mL solution of water containing 9.0 g of A using 25 mL ethyl acetate?

7

You have a sample of contaminated benzoic acid that weighs 2.014 g. After performing a proper recrystallization with proper drying, the mass of your purified benzoic acid is 1.611 g. What is your percent recovery rounded to the nearest tenths?

80

Which of the following wavenumber ranges corresponds to the fingerprint region in an IR spectrum? 1650-1750 cm-1 2900-3100 cm-1 3200-4000 cm-1 < 1500 cm-1

< 1500 cm-1

The partition coefficient of a neutral nonpolar organic Compound X is 22. What volume of organic solvent (in mL) is required to extract 99% of a 15 gram sample of Compound X from 75 mL of water in a SINGLE extraction? (1 pt) Hint: Based on the information in the question, what mass of Compound X should be in the organic layer? A. 338 mL of organic solvent B. 728mL of organic solvent C. 29mL of organic solvent D. 75 mL of organic solvent

A

You decide to use a plastic-backed TLC plate coated in silica gel. Which of the following choices is the stationary phase? A. The silica gel on the TLC plate B. The plastic of the TLC plate C. The solvent vapors in the developing chamber D. The substance or mixture to be separated E. The liquid solvent in the developing chamber

A

You wish to analyze the purity of a compound via TLC. If you wanted polar compounds to remain near the bottom (baseline) of the plate, what kind of TLC plate would you use A reverse phase TLC plate because the polar stationary phase will interact with polar compounds more strongly. A normal phase TLC plate because the nonpolar stationary phase will interact with nonpolar compounds more strongly. A reverse phase TLC plate because the nonpolar stationary phase will interact with polar compounds more strongly. A normal phase TLC plate because the polar stationary phase will interact with polar compounds more strongly.

A normal phase TLC plate because the polar stationary phase will interact with polar compounds more strongly.

Which of the following is an accurate description of the CEC method? A single enantiomer of alcohol is reacted with both enantiomers of HBTM A single enantiomer of alcohol is reacted with only one enantiomer of HBTM Both enantiomers of alcohol are reacted with both enantiomers of HBTM A single enantiomer of HBTM is reacted with both enantiomers of an alcohol

A single enantiomer of alcohol is reacted with both enantiomers of HBTM

You need to extract a nonpolar organic compound from 150 mL of aqueous solution. Which of the following changes will allow you to increase the recovery of your compound? Select all that apply. A. Perform two extractions using two 75 mL portions of organic solvent instead of one big extraction using 150 mL of organic solvent. B. Shake the two layers vigorously for an hour and then wait for an hour for the layers to separate C. Switch to an organic solvent in which your compound has a higher partition coefficient. D. Switch to an organic solvent in which your compound has a lower partition coefficient. E. Perform one big extraction using one 150 mL portion of organic solvent instead of two 75 mL portions of organic solvent.

A, C

You are separating anthracene from benzoic acid via an extraction between methylene chloride and a basic aqueous solution in a separatory funnel. How would you recover the benzoic acid? A. Collect the top layer and add HCl to precitipate the compound. B. Collect the top layer, dry with Na2SO4, and evaporate the solvent. C. Collect the bottom layer and add HCl to precipitate the compound. D. Collect the bottom layer, dry with Na2SO4, and evaporate the solvent. E. Collect the bottom layer and add NaOH to precipitate the compound. F. Collect the top layer and add NaOH to precipitate the compound.

A. Collect the top layer and add HCl to precitipate the compound.

Consider a situation where you were able to develop TLC conditions to analyze and visualize a mixture of the starting alcohol and the alkene product in the Elimination experiment using a reverse phase TLC plate. Which compound would have the higher retention factor? A. the alcohol B. both compounds would have the same retention factor C. cannot be predicted D. the alkene

A. the alcohol

A compound possessing a carboxylic acid produces a yellow solution when dissolved in diethyl ether. This yellow solution is transferred to a separatory funnel and an aqueous solution of sodium chloride is added as well. After mixing the two solutions and allowing them to settle, two layers form. Which of the following statements is true about the resulting layers? A. The bottom layer will be diethyl ether, and bottom layer will be yellow. B. The top layer will be diethyl ether, and the top layer will be yellow. C. The bottom layer will be diethyl ether , and the top layer will be yellow. D. The top layer will be diethyl ether, and the bottom layer will be yellow.

B. The top layer will be diethyl ether, and the top layer will be yellow. That is correct. Diethyl ether is less dense than water. Sodium chloride will not react with the carboxylic acid, and the carboxylic acid will remain in the diethyl ether layer.

Consider the reaction performed in the SN1 lab. What would be the effect on the rate of the reaction if 2-butanol was used instead of 2-methyl-2-butanol assuming only an SN1 reaction occurs? A. The rate of the reaction would increase, because the secondary carbocation is more easy to form. B. There would be no difference in reaction rate. C. The rate of the reaction would decrease, because the secondary carbocation is more difficult to form. D. The reaction would not proceed at all.

C

Let's push a little bit. You perform an SN1 reaction on a tertiary alcohol using 1 equivalent of hydrochloric acid. If you performed the same reaction using 10 equivalents of hydrochloric acid, what would you expect to be the result? A. The rate of reaction would be unaffected. B. The rate of the reaction would decrease. C. The rate of the reaction would increase. D. The extra acid would react with itself.

C

You know the Bayer test is used to identify the presence of alkenes. You attempt to perform an elimination reaction and test what you hope is the product using the Bayer test. Adding KMnO4 to a solution of the starting material requires 2 drops to remain purple, with no precipitate observed. A solution of your potential product requires 15 drops to remain purple, with no precitipate observed. Did you successfully perform an elimination reaction? A. No, because no precipitate was observed. B. No, because the solution of potential product took more drops of KMnO4 to remain purple. C. Yes, because the solution of potential product took more drops of KMnO4 to remain purple. D. Yes, because no precipitate was observed.

C

Select the bond that would absorb the highest wavenumber of light in an IR experiment. C-N single bond C-N double bond C-N triple bond Cannot be determined

C-N triple bond (triple bonds absorb higher ppm)

You are separating anthracene from benzoic acid via an extraction between ethyl acetate and a basic aqueous solution in a separatory funnel. How would you recover the anthracene? A. Collect the top layer and add HCl to precipitate the compound. B. Collect the bottom layer and add NaOH to precipitate the compound. C. Collect the bottom layer and add HCl to precipitate the compound. D. Collect the top layer, dry with Na2SO4, and evaporate the solvent. E. Collect the top layer and add NaOH to precipitate the compound. F. Collect the bottom layer, dry with Na2SO4, and evaporate the solvent.

Collect the top layer, dry with Na2SO4, and evaporate the solvent.

The final product of the Elimination experiment was a liquid. Let us say that you wanted to purify that product via a recrystallization of the type you have performed in this course. Would that be feasible? A. Yes, because a recrystallization only requires that the desired compound dissolves in a sovlent of some kind B. No, because a recrystallization only requires that the desired compound dissolves in a sovlent of some kind C. Yes, because a recrystallization requires that a compound forms solid crystals and the product is a liquid D. No, because a recrystallization requires that a compound forms solid crystals and the product is a liquid

D. No, because a recrystallization requires that a compound forms solid crystals and the product is a liquid

Your silica gel TLC plate, shown below, was visualized using UV light. Performing other analytical techniques on your sample reveal that there are four compounds present, yet you see only three spots. What can you definitively say about the unseen fourth compound? A. The fourth compound does not visualize in iodine B. The fourth compound is not polar C. The fourth compound is polar D. The fourth compound does not E. The fourth compound does not visualize under UV light

E. The fourth compound does not visualize under UV light

How will you distinguish your unknown aldehyde from your unknown ketone

IR

In the previous question, you recovered a mass of benzoic acid that was less than the mass you started with. What are explanations for the reduction in mass? Select all that apply There was a chemical reaction that consumed some of the benzoic acid Impurities were removed in the recrystallization process Some of the benzoic acid evaporated Some of the benzoic acid remained dissolved even at cold temperatures Some of the benzoic acid remained dissolved even at cold temperatures.Some of the benzoic acid remained dissolved even at cold temperatures.

Impurities were removed in the recrystallization process Some of the benzoic acid remained dissolved even at cold temperatures

Switching from a less polar eluent to a more polar eluent using a normal phase TLC plate will have what consequence? Increasing the polarity of the eluent has no effect on how far compounds elute. Increasing the polarity of the eluent causes all compounds to elute a longer distance. Increasing the polarity of the eluent causes only nonpolar compounds to elute a longer distance. Increasing the polarity of the eluent causes only polar compounds to elute a longer distance.

Increasing the polarity of the eluent causes all compounds to elute a longer distance.

Why is it important to frequently vent your separatory funnel when performing extractions? It allows for the escape of unwanted impurities. Continuously adding fresh air will accelerate the extraction process. It allows you to add more solvent over the course of the extraction process. It releases potentially dangerous pressure that has built up during the extraction process.

It releases potentially dangerous pressure that has built up during the extraction process.

Select all of the following lab techniques that you will utilize in the Recystallization experiment. (1 pt) Thin Layer Chromatography Melting Point Recystallization Spectroscopy

Melting Point Recystallization

What will you use to definitively identify your product after you have narrowed the possibilities? NMR spectroscopy melting point mass spectroscopy infrared spectroscopy

NMR spectroscopy

You are given a mixture of two acids, Acid A and Acid B. Acid A is a carboyxlic acid, and Acid B is a phenol. Which of the following aqueous solutions would you use to separate the two acids via a liquid/liquid extraction? Na2CO3 NaCl NaOH HCl

Na2CO3 (weak base. you want to deprotonate one of them without deprotonating the other)

You are given a 50:50 mixture of Compound A and Compound B. Both compounds have a K value of 1.5. Can you separate the compounds via an extraction Yes, because Compound A will prefer the organic layer more than Compound B. Yes, because Compound B will prefer the organic layer more than Compound A. No, because both compounds are insoluble in the organic layer. No, because Compound A and Compound B have the same solubility in both layers.

No, because Compound A and Compound B have the same solubility in both layers.

Is it acceptable to mark the baseline (the starting line 1 cm from the plate bottom) using a pen? Yes, because the ink will be easily distinguishable from any other compounds on the plate. Yes, because the ink will not elute up the plate. No, because the ink will react with the silica plate, causing an explosion. No, because the ink will elute up the plate and potentially obscure important data.

No, because the ink will elute up the plate and potentially obscure important data.

A particular compound has a K value of 1.4 when using an organic solvent and an aqueous solvent. Which phase does the compound prefer? It prefers both phases equally Organic solvent Aqueous solvent It will not dissolve in either phase

Organic solvent

A fractional distillation involves the use of a fractionating column to provide multiple condensation/evaporation cycles over a given distance (T/F)

T

Electrospray ionization is a soft ionization technique. (T/F)

T

The driving force for the aldol condensation you performed was the thermodynamic stability gained from making a conjugated carbon-carbon double bond. (T/F)

T

The fingerprint region is a difficult to interpret area of an IR spectrum (T/F)

T

Vial A and Vial B will be stopped independently of each other after each reaction has been allowed to run for one hour, meaning they will be quenched at different times. (T/F)

T

How does an acid/base extraction separate two compounds in a mixture with similar solubilities? The added acid or base makes a third layer, allowing for easier transfer between the aqueous and organic layers. The added acid or base performs a chemical reaction with one of the compounds to make a new species that precipitates out of solution, leaving the other compound behind. The added acid or base changes the polarity of the aqueous layer, thus allowing for separation of compounds. The added acid or base performs a chemical reaction with one of the compounds to make a new species with different solubility, thus allowing for separation.

The added acid or base performs a chemical reaction with one of the compounds to make a new species with different solubility, thus allowing for separation.

After performing a recrystallization, you calculate a percent recovery of 110%. Select all possible reasons for this result. The crystals were not dried properly after the recrystallization The recrystallized solid became more dense, increasing its mass Some of the solid melted during the weighing process, increasing its mass

The crystals were not dried properly after the recrystallization

When placed inside of a magnetic field, the magnetic field that electrons generate aligns in the opposite direction of the applied magnetic field. This has what effect on the nucleus the electrons are around?

The electrons shield the nucleus from the magnetic field

After brominating an alkene, you isolate a solid that is orange in color. The product is known to be a white solid when pure. What do you expect the result of performing a melting point analysis on the product to be? The melting point will be higher than the melting point of the pure compound The product will not melt The melting point will be lower than the melting point of the pure compound

The melting point will be lower than the melting point of the pure compound

Which of the following electrospray ionization mass spectra corresponds to a compound that contains one bromine atom?

The one with 2 peaks of the same height

Which of the following electrospray ionization mass spectra corresponds to a compound that contains one chlorine atom?

The one with the 3:1 ratio

The below compound has a retention factor of 0.35 using a silica gel TLC plate and a particular solvent system. What would happen if you repeated the TLC analysis, but used a less polar solvent system? The retention factor would increase The retention factor would not change Impossible to determine The retention factor would decrease

The retention factor would decrease

A compound has a known melting point of 210 °C - 211 °C when pure. You are given a sample of the compound and peform a melting point analysis. The melting point of the sample is 204 °C - 208 °C. What does this result tell you? The sample is impure The sample is pure The purity of the sample cannot be determined

The sample is impure

As the temperature of a solvent decreases, what happens to the solubility of a solid being dissolved in the solvent? The solubility stays the same The solubility decreases The solubility increases The solubility of the solute only changes when lowering the temperature

The solubility decreases

When placed inside of a magnetic field, NMR active nuclei act in what way?

They align mostly in the same direction as the applied magnetic field

What is the purpose of the phenyl group on the stereocenter of HBTM? To act as a pi-stacking recognition point for the approaching alcohol To block one face of the HBTM catalyst, forcing approach of the alcohol from the other side To coordinate with the triethylamine to facilitate deprotonation To make the catalyst react with butyric anhydride faster

To block one face of the HBTM catalyst, forcing approach of the alcohol from the other side

What is the purpose of adding the aqueous sodium bicarbonate to your reaction mixture? To separate any remaining 2-methyl-2-butanol To separate any remaining 2-chloro-2-methylbutane To quench any remaining trace amounts of acid To remove any remaining bulk water

To quench any remaining trace amounts of acid

What is the purpose of adding magnesium sulfate as a drying agent? To absort the entire organic layer. To remove trace amounts of water in the organic layer. To remove trace amounts of organic solvent in the aqueous layer. To absorb the entire aqueous layer.

To remove trace amounts of water in the organic layer.

You develop and visualize a silica gel TLC plate and are not satisfied with the results. Which of the following experimental parameters would result in a change in retention factors if you were to modify them in a properly performed TLC analysis? Mark all that apply. changing the TLC plate stationary phase length of the TLC plate changing the solvent system polarity width of TLC plate

changing the TLC plate stationary phase, changing the solvent system polarity

Which of the following structures would you expect to have a carbonyl stretch above 1700 cm-1 in an IR spectrum? Select all that apply.

ester and aldehyde

You are given a solution of benzoic acid, anthracene, and ethyl 4-aminobenzoate in methylene chloride. If you perform an extraction with basic aqueous solution, the majority of what compounds will remain in the organic layer? anthracene benzoic acid ethyl 4-aminobenzoate There will be nothing in the organic layer

ethyl 4-aminobenzoate anthracene

You are deciding which solvents to use to develop your TLC plate. Order the following solvents from most polar to least polar where 1 is most polar and 3 is least polar.

isopropanol (H bonding), acetone (dipole), toluene (van der waals)

The stretch for a C-H bond where the carbon is sp2 hybridized would be located where on an IR spectrum?

just above 3000 cm-1 (3000-3100)

You recrystallize the product of a bromination reaction by dissolving the entire product in hot solvent, cooling to room temperature, and then collecting the solid that crystallized. However, you are disappointed with your yield. Select all of the following actions that would increase the amount of solid recovered from the recrystallization. performing a hot filtration while keeping all impurities dissolved cool the recrystallization solution in an ice bath before collecting the crystals while keeping all impurities dissolved increase the amount of solvent used in the recrystallization while keeping all impurities dissolved lower the amount of solvent used in the recrystallization while keeping all impurities dissolved

lower the amount of solvent used in the recrystallization while keeping all impurities dissolved cool the recrystallization solution in an ice bath before collecting the crystals while keeping all impurities dissolved

In the experiment, you added water to the reaction vessel after the reaction was complete, but we did not discuss why. Based on what happened after adding the water, which of the following is the reason for the addition of water? lower the solubility of the product in solution so it precipitated out increase the solubility of the product in solution so it precipitated out lower the solubility of the product in solution so it stayed in solution increase the solubility of the product in solution so it stayed in solution

lower the solubility of the product in solution so it precipitated out

Mass spectrometry separates compounds based on what characteristic?

mass/charge ratio

What will you use to narrow down the options for the identity of your product to 2 or 3 possibilities melting point mass spectroscopy NMR spectroscopy infrared spectroscopy

mp

The distillate you collect from your final simple distillation should have a head temperature (temperature at the thermocouple) of 80 °C to 85 °C. What does this temperature correspond to? roughly the boiling point of your desired alkene product roughly the boiling point of your starting alcohol roughly the boiling point of the diol roughly the boiling point of various impurities

roughly the boiling point of your desired alkene product (bp of the pure substance bc is went through the fractional distillation)

A separatory funnel contains methylene chloride and an aqueous solution of some kind. What comprises the bottom layer? A. the layer positions constantly switch B. the methylene chloride C. the solvents mix completely D. the aqueous solution

the methylene chloride

How would the IR spectrum of 2-chloro-2-methylbutane differ from the IR spectrum of 2-methyl-2-butanol? the spectrum for 2-methyl-2-butanol would have a strong stretch at approximately 1700 cm-1 while the spectrum of 2-chloro-2-methylbutane would not the spectrum for 2-methyl-2-butanol would have a strong, broad stretch at approximately 3500 cm-1 while the spectrum of 2-chloro-2-methylbutane would not the spectrum for 2-chloro-2-methylbutane would have a strong, broad stretch at approximately 3500 cm-1 while the spectrum of 2-methyl-2-butanol would not the spectrum for 2-chloro-2-methylbutane would have a strong stretch at approximately 1700 cm-1 while the spectrum of 2-methyl-2-butanol would not

the spectrum for 2-methyl-2-butanol would have a strong, broad stretch at approximately 3500 cm-1 while the spectrum of 2-chloro-2-methylbutane would not

After performing this week's double aldol condensation, you decide to analyze the product using thin layer chromatography. You develop a normal phase TLC plate and see two spots upon visualization. You suspect that one spot is the double aldol reaction product where elimination did not occur, and the second spot is the desired double aldol condensation product. If your suspicion is correct, which spot would correspond to the double aldol reaction product where elimination did not occur? the spot with the smaller Rf value both product would have the same Rf value, therefore one of the spots is another impurity the identify of the spot cannot be predicted the spot with the larger Rf value

the spot with the smaller Rf value

You are performing an SN1 reaction to transform an alcohol into an alkyl halide. You decide to see if the reaction is complete via TLC. You spot the reaction mixture on a silica gel TLC plate, develop the TLC plate, and visualize the TLC plate to produce the image shown below. Although product has been formed, the reaction is still incomplete as the alcohol used as the starting material is also still present. Which spot corresponds to the alkyl halide product? the bottom spot unable to be determined the top spot

the top spot

Which of the following is the proper order of addition of reagents in Vial A prior to quenching with methanol? R-HBTM -> unknown alcohol -> butyric anhydride + Et3N unknown alcohol -> R-HBTM -> butyric anhydride + Et3N S-HBTM -> unknown alcohol -> butyric anhydride + Et3N unknown alcohol -> butyric anhydride + Et3N -> S-HBTM unknown alcohol -> S-HBTM -> butyric anhydride + Et3N unknown alcohol -> butyric anhydride + Et3N -> R-HBTM

unknown alcohol -> S-HBTM -> butyric anhydride + Et3N

In this experiment, you are ...producing 2-methyl-2-butanol from 2-chloro-2-methylbutane via a carbocation intermediate. ...producing 2-methyl-2-butanol from 2-chloro-2-methylbutane without going through a carbocation intermediate. ...producing 2-chloro-2-methylbutane from 2-methyl-2-butanol without going through a carbocation intermediate. ...producing 2-chloro-2-methylbutane from 2-methyl-2-butanol via a carbocation intermediate.

...producing 2-chloro-2-methylbutane from 2-methyl-2-butanol via a carbocation intermediate.

The partition coefficient of a neutral nonpolar organic Compound X is 17. How much of a 25 gram sample of Compound X will be left behind in the 200 mL water layer following three extractions with 75 mL aliquots of an organic solvent?

.062

You intend to perform the double aldol condensation reaction in this week's experiment using Ketone X and Aldehyde Y. You mix 0.3 moles of Ketone X with 0.4 moles of Aldehyde Y. What is your theoretical yield in moles? Round to the nearest tenth

.2

You develop and visualize a TLC with two lanes. The compound in lane 1 eluted a distance of 3.0 cm. The compound in lane 2 eluted a distance of 6.0 cm. The solvent front eluted a distance of 12.0 cm. Calculate the retention factor of the compound in lane 1 to the hundredths place. (1 pt)

.25

Proton A couples to Proton B. Proton A posseses a J-value of 3.0 Hz. What do you expect the J-value Proton B posseses to be?

3.0 Hz

You developed the silica gel TLC plate using 100% ethyl acetate. Which of the following solvent systems would result in higher retention factors if you were to analyze the sample via TLC the same way again? The structures of ethyl acetate, ethanol, and hexane are shown below. 100% ethanol 50% ethanol/50% ethyl acetate 100% hexanes 50% hexanes/50% ethyl acetate

100% ethanol 50% ethanol/50% ethyl acetate

Which of the following electrospray ionization mass spectra corresponds to a molecule with a neutral molecular weight of 102 g/mol?

103 (H+) or 125 (Na+)

A carbon carbon triple bond would contribute how many degrees of unsaturation to a molecule?

2

How many degrees of unsaturation are present in a molecule with the molecular formula C5H8BrNO

2 ((2*5 + 2 + 1 - 8 - 1)/2)

A binary liquid mixture where the two components have a difference in boiling points of 20 °C can be effectively separated using a simple distillation (T/F)

F

A fractional distillation is less efficient (less capable of giving pure product) than a simple distillation (T/F)

F

Electrospray ionization mass spectroscopy often results in analyte molecules fragmenting. (T/F)

F

Increasing the mass of atoms connected by a bond results in the absorbance of a higher wavenumber of light. (T/F)

F

The condensation portion of an aldol condensation reaction proceeds through an E2 mechanism. (T/F)

F

The condensation portion of the aldol condensation reaction proceeds via an E1 mechanism (T/F)

F

You want to assess the purity of the product of this bromination experiment via 1H NMR spectroscopy. You would be able to see leftover Br2 in a 1H NMR spectrum (T/F)

F

A non-polar bond will always show a signal in an IR spectrum. (T/F)

F - symmetric bonds will not show up

Upon being added, the butyric anhydride reacts with what first? HBTM the unknown alcohol triethylamine toluene

HBTM (makes reactive intermediate)

For the Bayer test, you will add a solution of potassium permanganate to which of the following items? Select all that apply pure isolated liquid product pure starting liquid alcohol a solution of your starting alcohol a solution of you isolated product

a solution of your starting alcohol (should be purple, no alkenes) a solution of you isolated product (should be brown, indicating you actually did the reaction)

You perform an aldol reaction with the goal of not producing the aldol condensation product. You take an IR spectrum of the product. The presence of a stretch in which of the following regions in the IR would prove you were successful? a strong, broad stretch at ~3500 cm-1 a stretch at ~1700 cm-1 stretches just above ~3000 cm-1 stretches just below ~3000 cm-1

a strong, broad stretch at ~3500 cm-1 (indicates OH)

You are given a solution of benzoic acid, anthracene, and ethyl 4-aminobenzoate in methylene chloride. If you perform an extraction with acidic aqueous solution, the majority of what compounds will remain in the organic layer? Select all that apply anthracene benzoic acid ethyl 4-aminobenzoate None of the compounds

anthracene benzoic acid

Select all of the following compounds that are not considered highly polar, that is they do not form hydrogen bonding interactions alkanes amines carboxylic acids alcohols alkenes ethers

alkanes, alkenes, ethers

Which of the following types of carbonyl would generally have a stretch located below 1700 cm-1

amide (or conjugated carbonyls)