ocher 2 lab final

17. Which of the following is a drying reagent used in organic syntheses? sodium chloride magnesium chloride sodium bicarbonate potassium sulfate magnesium sulfate

magnesium sulfate

Theoretically, how many moles of a ketone can reduce one mole of sodium borohydride? 1 c. 3 e. 5 2 d. 4

4

In the esterification of benzoic acid with methanol, which of the following statements is true? 1. 2. 3. The excess methanol increases the yield of the ester. The H2SO4 catalyzes the reaction.Adding H2O will increase the yield of the ester. 1 only c. 2 and 3 e. 1, 2 and 3 1 and 3 d. 1 and 2

1 and 2

Which of the following classification tests will be positive for propanal? 1. 2,4-DNP 1 only 1and2 1and3 1, 2 and 3 1and4 2. Tollens' 3. Schiff's 4. Iodoform

1, 2 and 3

While performing a reaction at 150 C over 3 hours, you found that you obtained a product mixture containing a majority of the thermodynamic product. You would like a majority of the kinetic product. What reaction conditions would you use? 100 C over 1 hour 250 C over 5 hours 250 C over 3 hours 150 C over 5 hours 150 C overnight (16 hours)

100 C over 1 hour

A Grignard reaction of n-butylmagnesium bromide with acetone would produce: 3-methyl-2-hexanol 2-methyl-3-hexanol 2-hexyl-2-methanol 2-methyl-2-hexanol 1,1-dimethyl-1-pentanol

2-methyl-2-hexanol

In the addition of the HBr to butadiene, which product is the product of kinetic control? 1,4-dibromo-2-butene 1-bromo-3-butene 1-bromo-2-butene 3-bromo-1-butene 1,2-dibromo-3-butene

3-bromo-1-butene

What is the UVA range of light? 290-315 nm c. 100-290 nm 315-400 nm d. 400-700 nm e. 700-1000 nm

315-400 nm

In order to determine whether the desired type of functional group was produced in the Grignard Reaction, you obtained an IR spectrum. The characteristic peak that should have been present for the product was at approximately: 2400-2580 cm-1 d. 3010-3100 cm-1 3200-3600 cm-1 e. Fingerprint Region 1700-1720 cm-1

3200-3600 cm-1

In the preparation of methyl benzoate (MW=136), a student started with 24.4 g of benzoic acid (MW=122) and 37.5 mL of methyl alcohol (MW=32, density=0.8 g/mL). After separation and purification, 11.6 g of methyl benzoate was obtained and 5.4 g of benzoic acid was recovered. What is the percent yield based on the amount of benzoic acid actually consumed? 71% c. 55% e. 28% 61% d. 47%

55%

What is the key IR stretch for the aromatic substitution pattern of 5-iodosalicylamide? 770-730 cm-1; 1,2-disubstitute770-715 cm-1; monosubstituted790-750 cm-1; 1,2,3-trisubstituted 850-800 cm-1; 1,2,4-trisubstituted 910-830 cm-1; 1,3,5-trisubstituted

850-800 cm-1; 1,2,4-trisubstituted

which of the following statements about the base-catalyzed aldol condensation reaction is false? There must be alpha hydrogens present. An enolate ion is formed. A hydride transfer is an important step in the mechanism. The hydroxide ion acts as a catalyst. Two different aldehydes can give up to four different p

A hydride transfer is an important step in the mechanism.

Which of the following statements concerning the iodination of salicylamide reaction is false? Traces of 3-iodo and/or 3,5-diiodo substituted products are present in the reaction mixture because those positions are activated towards electrophilic substitution The reaction mixture is alkaline and therefore, it needs to be acidified at the end to make the solid product to precipitate Household bleach solution (NaOCl) aids in the production of the electrophile in situ by reacting with NaI The electrophile in the reaction is "I+" A significant amount of 4-iodosalicylamide will also be obtained in addition to major product because of the activating effect of the -CONH2 group on the aromatic ring

A significant amount of 4-iodosalicylamide will also be obtained in addition to major product because of the activating effect of the -CONH2 group on the aromatic ring

Substituents on an aromatic ring affect electrophilic aromatic substitutions in that: Activating groups make substitution more likely by donating electron density. Activating groups make substitution less likely by donating electron density. Deactivating groups make substitution more likely by donating electron density. Deactivating groups make substitution less likely by donating electron density. Deactivating groups make substitution more likely by withdrawing electron density.

Activating groups make substitution more likely by donating electron density.

Which of the following is true of the reaction of camphor with NaBH4? The major product is the endo product because of the bulky nature of NaBH4. The hydrogen that protonates the carbonyl oxygen comes from a hydride transfer from the NaBH4. NaBH4 is used instead of LiAlH4 because it much more reactive and will give the desired product in higher yields. An alkoxide intermediate is formed by a nucleophilic addition of a hydride from NaBH4 on the carbonyl carbon. None of the above are true

An alkoxide intermediate is formed by a nucleophilic addition of a hydride from NaBH4 on the carbonyl carbon.

Which of the following is not an amino acid? a. Aniline b. Tryptophan c. Glutamine d. Serinee. Lysine

Analine

The mixed aldol condensation gives a mixture of products because: The base attacks the carbonyls instead of forming the enolate. Both ketones have similar reactivity. An oxidation reaction can also take place. The hydroxide ion can cause substitution of one of the -hydrogens to give an alcohol. The reaction needs water to be selective.

Both ketones have similar reactivity.

The precipitate observed in a positive iodoform test is: Ag(I) c. CuI2 e. CHI3 d. CI4 an alcohol

CHI3

Which of the following cannot be used to cleave amide bonds? HCl KOH DCC trpysin serine protease

DCC

Which of the following polymers is a polyester comprising of identical repeating units? Wool c. Cotton e. Nylon Dacron 54 d. Creslan

Dacron 54

The reaction to form azo dyes is an example of what type of reaction? Nucleophilic aromatic substitution Nucleophilic acyl substitution Electrophilic addition Electrophilic aromatic substitution SN2 substitution

Electrophilic aromatic substitution

In the borohydride reduction of camphor, NaBH4 provides _______ to reduce camphor. a. H- c. H e. H2Ob. H+ d. H2

H-

35. In the esterification reactions to produce fragrant esters, the catalyst used was? HNO3 c. Mg e. NaOH H2SO4 d. NaHCO3

H2SO4

Benzoyl chloride can react with water in your eye. What is a product of this reaction, and what risky substance is benzoyl chloride classified as?

HCl, lachrymator

What species is responsible for generating the diazonium intermediate during the synthesis of the azo-dye? NaNO2 c. HNO3 e. HNO2 HCl d. NaOH

HNO2

Many proteins react with their substrates through acid-base chemistry. Which of the following amino acid residues would work the best for removing a proton from a substrate? a. Histidineb. Isoleucinec. Asparagined. Valinee. Phenylalanine

Histidine

Choose the right order of increasing energy of radiation from the lowest frequency to the highest frequency IR, visible, UV d. visible, UV, IR UV, visible, IR e. UV, IR, visible visible, IR, UV

IR, visible, UV

Which of the following reagent(s) can be used to reduce camphor in ethanol? LiAlH4 c. Na e. either a or b can be used NaBH4 d. Al

NaBH4

Which pair of reactants is responsible of the formation of the azo salt in the diazotization of an aromatic primary amine? Na2CO3 and H2O d. NaNO2 and HCl Na2CO3 and HCl e. NaNO2 and Na2CO3 Na2CO3 and NaNO3

NaNO2 and HCl

Which of the following stains was used in the peptide and amino acid lab on the TLC plate? KMnO4 d. Dragendorff's reagent Ceric Nitrate e. None of these Ninhydrin

Ninhydrin

The aldol reaction between dibenzyl ketone and benzil is synthetically useful because of which of the a. b. c. d. e. following?The two carbonyl compounds have similar reactivity.There is a large difference in the reactivity of the carbonyl groups.One of the compounds has no alpha-hydrogens.They are two different carbonyl compounds which is a requirement for the reaction. The product crystallizes from solution and drives the reaction to completion.

One of the compounds has no alpha-hydrogens.

Which of the following polymers/fabrics cannot bind a polar organic dye strongly? Silk Wool Nylon 66 Filament acetate Polyester

Polyester

Functionally, proteins are Long chain carboxylic acids Polymeric glycols Poly amines Long chain fatty acids Polymeric peptides

Polymeric peptides

Which of the following statements is false? The R-Mg bond is a very polar covalent bond. Grignard reagents react with acids to give alkanes. The alkyl group of a Grignard reagent acts as a powerful electrophile with nucleophilic compounds. Preparation and reactions of Grignard reagents may be carried out with an ether as solvent. Grignard reagents react with atmospheric carbon dioxide to form carboxylic acids.

Preparation and reactions of Grignard reagents may be carried out with an ether as solvent.

Which of the following items is false about the UV analysis of sunscreens experiment? UV-Vis spectroscopy detects the electronic transitions of conjugated systems one can use UV-Vis analysis to measure the concentration of some products SPF only refers to product effectiveness against the UVA rays of the sun many sunscreen agents are composed of aromatic rings in conjugation with other functional groups ultraviolet frequencies correspond to shorter wavelengths compared with infrared spectroscopy

SPF only refers to product effectiveness against the UVA rays of the sun

In the iodination of salicylamide, what reagent was acting as the nucleophile in this reaction? NaOCl c. Salicylamide NaI d. Na2S2O3 e. Ethanol

Salicylamide

Which one is not a derivative of carboxylic acids? esters carboxylic acid anhydrides acid chlorides amides Schiff's base

Schiff's base

Which method is used to determine the structure of an enzyme? NMR Powder x-ray IR UV Single-crystal x-ray crystallography

Single-crystal x-ray crystallography

Which of the following statements is NOT true? The affinity of a dye for a particular fabric depends only on the fabric's structure. Diazonium salts are usually not stable at high temperatures. Reduction of indigo to leucoindigo is accompanied by a drastic change in the color of its solution. The pipet bulb with the slit used in the reduction of indigo ensures constant pressure is maintained in the reaction flask. The highly polar groups on Nylon provide sites for hydrogen bonding to dye molecules.

The affinity of a dye for a particular fabric depends only on the fabric's structure

Which of the following statements is not an important practice in maximizing the yield in a Grignard synthesis? a. All reactants, solvents, and reagents should be dry.b. The alkyl halide should be added to the Mg only fast enough to maintain reflux. c. The carbonyl compound should be added quickly to the Grignard reagent.d. The Mg salts formed during hydrolysis should be decomposed with a dilute acid. e. All of these are necessary practices.

The carbonyl compound should be added quickly to the Grignard reagent.

If a certain sunscreen has a UV absorbance of 0.62 at 360 nm and an absorbance of 0.45 at 310 nm, what can be inferred about that sunscreen? The sunscreen is better at protecting against UVA radiation. The sunscreen is better at protecting against UVB radiation. The sunscreen shows zero protection against UV radiation. The sunscreen mostly absorbs light in the visible light region. The sunscreen has a higher concentration at 360 nm than at 310 nm.

The sunscreen is better at protecting against UVA radiation.

Avobenzone and oxybenzone are sunscreen ingredients that both protect against ____ rays. UVB c. UVC e. UVA and UVC UVA d. UVA and UVB

UVA and UVB

A local energy minimum would represent: the most probable conformationthe least probable conformationthe closest substituents to the center of the moleculethe least reactive conformationa conformation at an energy minimum that does not have the lowest possible energy

a conformation at an energy minimum that does not have the lowest possible energy

Isopentyl acetate has a pleasant smell of bananas. What two reagents can this ester be made from? acetone and isopentyl alcohol isopentanoic acid and ethanol acetaldehyde and isopentyl ether acetic acid and isopentyl alcohol isopentanoic acid and acetic alcohol

acetic acid and isopentyl alcohol

Which set represents derivatives of carboxylic acids? esters, alcohols, amines acid chlorides, thiols, nitriles esters, acid chlorides, amines acid chlorides, alcohols, ketones acid chlorides, amides, esters

acid chlorides, amides, esters

A KMnO4 test will detect the presence of a. alcohols b. esters c. amines d. ketones e. ethers

alcohols

The Schiff's reagent gives a positive test for ____________ by giving ____________. alkenes; a yellow precipitate.methyl ketones; a yellow precipitate. aldehydes; a wine-purple color. methyl ketones; a red precipitate. alkenes; a purple color.

aldehydes; a wine-purple color.

Amides can be prepared in one step by reacting an amine with a carboxylic acid c. an acid chloride e. an aldehyde d. a bromohydrin an alcohol

an acid chloride

What is the intermediate formed during the reaction of an aldehyde and base in the first step of an aldol condensation? an enol c. an alcohol e. none of these an aldol d. an enolate

an enolate

The two possible starting materials for preparing an azo dye are: 2-nitrobenzaldehyde and acetone aniline and phenol nitrobenzene and acetone 2-nitrobenzaldehyde and phenol aniline and benzaldehyde

aniline and phenol

What should be done to neutralize a bromine or an iodine burn? apply sodium sulfate solution apply sodium bicarbonate solution apply dilute acetic acid solution apply potassium permanganate solution apply sodium thiosulfate solution

apply sodium thiosulfate solution

Aspartame is one of the most common alternatives to sugar. It is a dipeptide of _______. alanine and glycine aspartic acid and alanine phenylalanine aspartic acid and phenylalanine none of these

aspartic acid and phenylalanine

Which of the compounds below is a lachrymator? methanol benzoyl chloride sodium hydroxide d. sodium chloride e. none of these

benzoyl chloride

Amide bonds may be broken by all of the following except: under basic conditions under acidic conditions enzymatically by reaction with dichloromethane with trypsin

by reaction with dichloromethane

Which of the following will not react with a diazonium salt to produce an azo dye? 2-naphthol cyclohexanol salicylic acid 1-naphthol all of the above will give a dye

cyclohexanol

In the aldol condensation of dibenzyl ketone and benzil to form TPCP, __________ first loses a proton to form the enolate. TPCP benzil dibenzyl ketone KOH ethanol

dibenzyl ketone

Amide bonds in living systems are hydrolyzed under __________ . a. enzymatic conditions b. acidic conditionsc. rough conditionsd. basic conditionse. acidic and basic conditions

enzymatic conditions

To obtain the UV spectrum of sunscreen ingredients, we dissolved the samples in: ethanol c. water e. isopropyl alcohol hexanes d. methanol

isopropyl alcohol

The ammonium chloride solution was used in the Grignard reaction to: facilitate formation of the Grignard reagent hydrolyze the magnesium alkoxide to form the product alcohol activate the acetone for addition to the Grignard reagent moderate the reaction so it would not get too vigorous convert the Grignard to a halide by SN1 substitution

hydrolyze the magnesium alkoxide to form the product alcohol

A KMnO4 test on the basic hydrolysis products of aspartame will detect the presence of a. methyl alcohol b. amide bondsc. ethanold. free aminese. free carboxylic acids

methyl alcohol

Which of the following is the LEAST volatile? ethyl acetate methyl formate methyl salicylate ethyl pentanoate

methyl salicylate

In comparison to LiAlH4, sodium borohydride is a ______ reducing agent that is capable of reducing ______. milder; amides and carboxylic acids more powerful; aldehydes, carboxylic acids, esters and amides more powerful; esters, ketones and amides milder, aldehydes and ketones aandd

milder, aldehydes and ketones

Given the structure of salicylamide, where would you expect the I+ to add on the ring in an electrophilic aromatic substitution?

on the meta position

What is the classification of an enzyme?

proteins

A catalytic amount of mineral acid in Fischer esterification of a carboxylic acid: protonates the carbonyl oxygen of the carboxylic acid, generating a reactive, resonance stabilized electrophilic species. protonates the OH of the carboxylic acid to generate a reactive, resonance stabilized electrophilic species. protonates the alcohol and forms an alkene. increases the product yield. changes the equilibrium to favor ester formation.

protonates the carbonyl oxygen of the carboxylic acid, generating a reactive, resonance stabilized electrophilic species.

The analogy between a chemical bond and a mechanical spring is very approximate, since electrons and atoms are governed by ___________. kinetic control thermodynamic control ab initio methods quantum mechanics Newtonian mechanics

quantum mechanics

What two processes were catalyzed by the enzymes investigated in the Visualization of Proteins experiment? oxidation and decarboxylation hydrolysis and oxidation hydrolysis and racemization phosphorylation and decarboxylation racemization and decarboxylation

racemization and decarboxylation

You are trying to carry out the acid-catalyzed esterification of benzoic acid with ethanol. Which of the a. b. c. d. e. following would not lead to a higher yield of the ester? excess ethanolreact benzoic acid with thionyl chloride firstexcess benzoic acid removal of water by distillation removal of ethanol by distillation

removal of ethanol by distillation

The equilibrium of a Fischer esterification can be shifted to yield more ester by: increasing the amount of catalyst used raising the temperature of the reaction removal of water use of a mineral acid catalyst using air sensitive techniques for the reaction conditions

removal of water

The reaction of a Grignard reagent with most aldehydes produces a __________ alcohol and the reaction of a Grignard reagent with a ketone produces a __________ alcohol primary, secondary d. primary, primary secondary, tertiary e. tertiary, tertiary primary, tertiary

secondary, tertiary

In the Aldol Condensation experiment a computer was used to analyze the TPCP molecule. One of the questions asked was why the molecule is not completely planar. What prevents this molecule from being planar? it is not aromatic steric interactions between the phenyl groups conjugation is maximized with phenyl groups perpendicular to 5-membered ring. attraction between systems of aromatic rings 5-membered ring is puckered.

steric interactions between the phenyl group

In the borohydride reduction of camphor, borneol is: the major product because endo addition is less favorable the minor product because an axial hydroxy is less stablethe minor product because exo addition is less favorablethe major product because endo addition is more favorable the major product because an equatorial hydroxyl is unstable

the minor product because exo addition is less favorable

Which of the following statements is not true about the Grignard reaction? The reaction of a Grignard reagent with butanone is endothermic. Adding iodine can facilitate the preparation of Grignard reagent. Ammonium chloride was used to hydrolyze the magnesium alkoxide. An ester will react with 2 moles of Grignard reagents to form a tertiary alcohol. The solvent can form a soluble complex with a Grignard reagent.

the reaction of a Grignard reagent with butanone is endothermic.

For most organic reactions that produce more than one product, what is generally the most important factor determining the ratio of products? the relative energies of the transition states that produce the two products the relative energies of the two final products the relative energies of the starting materials and the reagents all of the above are equal factors bothbandc

the relative energies of the transition states that produce the two products

Which is not true in using acid chloride with an alcohol in the synthesis of an ester? gives higher yield d. room temperature reaction does not require excess alcohol e. uses acid as catalyst byproduct HCl can be easily removed

uses acid as catalyst

Which of the following may give you a false positive result in 2,4-DNP test? doing the test at pH 4-5 adding drops of water into the reagent mixture adding drops of ethanol into the reagent mixture washing the glassware with water without flushing away water with acetone washing the glassware with acetone without letting it evaporate

washing the glassware with acetone without letting it evaporate