Archive for June 2018

There are several chemical classification tests that can discern the difference between aldehydes and ketones, and also provide partial structure determination. Identify the components of the iodoform test reagent by dragging the reagent labels into the box.

There are several chemical classification tests that can discern the difference between aldehydes and ketones, and also provide partial structure determination. Identify the components of the iodoform test reagent by dragging the reagent labels into the box.



Answer:


  • Sodium hydroxide
  • Potassium Iodide
  • Iodine

The nitrating mixture of concentrated nitric and sulfuric acids is very corrosive. Nitric acid will burn and stain your skin yellow, while sulfuric acid will cause serious dehydrating tissue damage. Which of the following actions should you follow if you spill the nitrating mix on your jeans?

The nitrating mixture of concentrated nitric and sulfuric acids is very corrosive. Nitric acid will burn and stain your skin yellow, while sulfuric acid will cause serious dehydrating tissue damage. Which of the following actions should you follow if you spill the nitrating mix on your jeans?



Answer: Proceed immediately to the safety shower

There are several chemical classification tests that can discern the difference between aldehydes and ketones, and also provide partial structure determination. Identify the components of the Schiff's test reagent by dragging the reagent labels into the box.

There are several chemical classification tests that can discern the difference between aldehydes and ketones, and also provide partial structure determination. Identify the components of the Schiff's test reagent by dragging the reagent labels into the box.



Answer:

sodium bisulfite
rosaniline hydrochloride

The use of rinse acetone to remove traces of water from glassware is a very common laboratory technique. When performing qualitative tests in glass test tubes, such as Iodoform test or dinitrophenylhydrazine test, why should you avoid rinsing the glassware with acetone prior this experiment?

The use of rinse acetone to remove traces of water from glassware is a very common laboratory technique. When performing qualitative tests in glass test tubes, such as Iodoform test or dinitrophenylhydrazine test, why should you avoid rinsing the glassware with acetone prior this experiment?



Answer: It will give a false positive for some carbonyl classification tests.

A reaction was performed, and the dichloromethane solvent was dried by adding magnesium sulfate drying agent. When the reaction flask was shaken, it was observed that the magnesium sulfate swirled around freely at the bottom of the flask. What does this observation indicate?

A reaction was performed, and the dichloromethane solvent was dried by adding magnesium sulfate drying agent. When the reaction flask was shaken, it was observed that the magnesium sulfate swirled around freely at the bottom of the flask. What does this observation indicate?



Answer: the correct amount of drying agent has been used

Which of the following statements is false about Grignard Reaction?

Which of the following statements is false about Grignard Reaction?



a. The Grignard reagent may be viewed as a strong base.
b. Grignard reagents are prepared by the reaction of alkyl or aryl halides with magnesium.
c. Grignard reagents are most often used in reactions with aldehydes or ketones.
d. Grignard reagents react with acids to give alkanes.
e. Alcohols are often used as solvents in the Grignard Reactions.

List the procedural steps, from start to finish, that are required to convert dibenzyl ketone and benzil into tetraphenylcyclopentadienone.

List the procedural steps, from start to finish, that are required to convert dibenzyl ketone and benzil into tetraphenylcyclopentadienone.



1) equip round bottom flask with air condenser
2) add solution of dibenzyl ketone and benzil in ethanol to the flask/condenser assembly
3) warm the flask on a steam bath
4) add a pre-prepared solution of ethanolic KOH into reaction mix, slowly down the condenser
5) heat the purple reaction mix under reflux for 15 mins
6) cool the reaction flask in an ice bath
7) collect purple crystals by vacuum filtration

List the procedural steps, from start to finish, that are required to prepare indigo from nitrobenzaldehyde and acetone in base, and then test its ability as a dye.

List the procedural steps, from start to finish, that are required to prepare indigo from nitrobenzaldehyde and acetone in base, and then test its ability as a dye.




1) Mix 2-nitrobenzaldehyde and acetone in a test tube, then slowly add sodium hydroxyde
2) Collect the purple precipitate by filtration and wash with water followed by ethanol
3) Fit a slit pipette bulb over the side arm of a filter flask
4) Place solid indigo into pre-prepared filter flask and heat vigorously with sodium hydroxide solution in the stoppered flask
5) Add sodium dithionate until the hot solution is a clear yellow
6) Place a fabric strip into the hot solution and heat for 10 minutes
7) Remove the strip, rinse with water, and record the color when dry

List the procedural steps, from start to finish, that are required for the correct use of an automatic micropipette.

List the procedural steps, from start to finish, that are required for the correct use of an automatic micropipette.



1) check that the pipette is set to dispense at the correct volume
2) depress the knob until the point of initial resistance is reached
3) immerse the tip of the pipette into the solution
4) slowly release the plunger to draw solution into the tip
5) withdraw the tip from the solution, then place the tip on the internal wall of the container the solution should be dispensed into
6) depress the knob to the initial point of resistance for a second time
7) pause, then depress the knob as far as it will travel

List the procedural steps, from start to finish, that are required in the sodium borohydride reduction of camphor to isoborneol.

List the procedural steps, from start to finish, that are required in the sodium borohydride reduction of camphor to isoborneol.




1. dissolve camphor in ethanol in an erlenmeyer flask
2. carefully add an excess of sodium borohydride
3. let the reaction mixture stand for 10 mins
4. heat to a gentle boil for 10 mins
5. pour reaction mixture in a beaker of ice water
6. collect the precipitate by vacuum filtration, and blot dry
7. recrystallize from methanol and water

List the procedural steps, from start to finish, that are required to generate a low molecular mass ester, and to characterize it by smell.

List the procedural steps, from start to finish, that are required to generate a low molecular mass ester, and to characterize it by smell.



1) add 10 drops of liquid carboxylic acid to a clean dry test tube
2) smell the acid by wafting your hand over the open tube
3) add 10 drops of alcohol to the carboxylic acid
4) add 5 drops of concentrated sulfuric acid to the mixture
5) shake the tube then place in warm water bath for 20 minutes
6) allow to cool, and pipet out the organic layer onto watch glass
7) allow any excess alcohol time to evaporate, then smell the ester by wafting your hand over the watch glass

How does adding a Brønsted acid help the reaction?

How does adding a Brønsted acid help the reaction?




a) Once protonated, the hydroxyl group of the alcohol becomes more susceptible to attack by the carboxylic acid.
b) The water produced by the reaction is incapable of being a nucleophile for the reverse reaction if it is protonated.
c) The acid catalyzes only the forward reaction.
d) The carbonyl group of the carboxylic acid becomes more susceptible to attack by nucleophiles if the carbonyl oxygen is protonated.


Answer: b) The water produced by the reaction is incapable of being a nucleophile for the reverse reaction if it is protonated.
And
d) The carbonyl group of the carboxylic acid becomes more susceptible to attack by nucleophiles if the carbonyl oxygen is protonated.

List the procedural steps, from start to finish, that are required to convert benzoic acid into methyl benzoate via a Fischer esterification.

List the procedural steps, from start to finish, that are required to convert benzoic acid into methyl benzoate via a Fischer esterification.



1) dissolve the benzoic acid in methanol in a round bottom flask
2) add conc. sulfuric acid and heat under reflux on a steam bath
3) pour the reaction mix into ice, and rinse the reaction flask with dichloromethane. Collect the combined layers in test tube
4) wash the dichloromethane layer with sodium carbonate solution, followed by a wash with sodium chloride solution
5) dry the dichloromethane solution over magnesium sulfate
6) remove the dichloromethane by distillation on a steam bath
7) distill the remaining liquid ester in a vial on a heating mantle

Methyl benzoate undergoes a nitration by electrophilic aromatic substitution when reacted with a mixture of concentrated nitric and sulfuric acids. List the procedural steps in order to convert methyl benzoate into methyl nitrobenzoate.

Methyl benzoate undergoes a nitration by electrophilic aromatic substitution when reacted with a mixture of concentrated nitric and sulfuric acids. List the procedural steps in order to convert methyl benzoate into methyl nitrobenzoate.



1) add methyl benzoate to ice-cold concentrated sulfuric acid
2) Dropwise, add an ice-cold mixture of sulfuric and nitric acids
3) Swirl the contents of the flask and then allow it to warm to room temp
4) stir the room temperature reaction mixture for ten minutes
5) slowly pour the reaction mixture over crushed ice
6) collect the solid product by vacuum filtration
7) crush the solid crystals on the filter and wash them with cold water followed by ice-cold methanol

2-Butanone is converted into 3-methyl-3-hexanol using a Grignard reagent prepared from 1-bromopropane and magnesium metal in THF solution. List the procedural steps required to collect the alcohol product by microdistillation.

2-Butanone is converted into 3-methyl-3-hexanol using a Grignard reagent prepared from 1-bromopropane and magnesium metal in THF solution. List the procedural steps required to collect the alcohol product by microdistillation.




Answer:

1) decant the dried THF solution into 25-mL round-bottom flask
2) add boiling chips to the solution in round-bottom flask
3) grease all joints and attach the flask to a micro distillation apparatus
4) set apparatus in heating mantle and use heat shield tiles
5) adjust Variac to distill THF at ~60ºC
6) Increase Variac setting to cause distillation of higher-boiling product
7) stop distillation before the flask becomes dry

In a Grignard reagent, the bond between carbon and magnesium is covalent, but highly polarized. Complete the sentence: Therefore, the carbon reacts as if it was a ________ and is a __________ and a good ________.

In a Grignard reagent, the bond between carbon and magnesium is covalent, but highly polarized. Complete the sentence: Therefore, the carbon reacts as if it was a ________ and is a __________ and a good ________.



Answer: Therefore, the carbon reacts as if it was a carbanion and is a strong base and a good nucleophile

Grignard reactions are highly exothermic and are performed in ether solvent. There is a real risk of fire during this reaction. In the case that a fire should occur in your distillation apparatus, what is the best course of action?

Grignard reactions are highly exothermic and are performed in ether solvent. There is a real risk of fire during this reaction. In the case that a fire should occur in your distillation apparatus, what is the best course of action?


Answer: Smother the flames with a watch glass or beaker.

Why are ethers commonly used as a solvent for Grignard reagent preparations?

Why are ethers commonly used as a solvent for Grignard reagent preparations?




a) Ethers are non-toxic and non-flammable.
b) Ether's high vapor pressure helps to prevent moisture from entering the reaction vessel.
c) Ethers have high boiling points, so the reaction can be performed hot.
d) The lone-pairs of electrons on the ether solvate the magnesium ion.


Answer: b) Ether's high vapor pressure helps to prevent moisture from entering the reaction vessel.
and
d) The lone-pairs of electrons on the ether solvate the magnesium ion.

List the procedural steps, from start to finish, that are required to convert 2-butanone into 3-methyl-3-hexanol using a Grignard reagent prepared from 1-bromopropane and magnesium metal.

List the procedural steps, from start to finish, that are required to convert 2-butanone into 3-methyl-3-hexanol using a Grignard reagent prepared from 1-bromopropane and magnesium metal.




1) dry all glassware and reagents prior to starting the experiment
2) add 1-bromopropane to clean magnesium
3) wait for reaction to turn cloudy. Sonicate if necessary
4) add 2-butanone dropwise to the grignard reagent, allowing a gentle reflux
5) add aqueous ammonium chloride to quench the reaction
6) wash the reaction mixture with sodium bicarbonate and sodium chloride solutions in a separatory funnel
7) dry over magnesium sulfate and distill product from THF

During the preparation of a tertiary alcohol by a Grignard reaction, the reaction mixture was shaken with saturated sodium chloride solution. What is the purpose of the saturated sodium chloride solution?

During the preparation of a tertiary alcohol by a Grignard reaction, the reaction mixture was shaken with saturated sodium chloride solution. What is the purpose of the saturated sodium chloride solution?




a) Saturated sodium chloride decreases the solubility of the organic product in water.
b) Saturated sodium chloride raises the density of the aqueous layer so that it will be the bottom layer.
c) Saturated sodium chloride causes the water to be immiscible with the THF.
d) Saturated sodium chloride lowers the boiling point of the water.


Answer: a) Saturated sodium chloride decreases the solubility of the organic product in water.

Benzophenone reacts with phenylmagnesium bromide in ether solution to make triphenylmethanol after acid workup. Which of the following experimental mistakes will decrease the effectiveness of a Grignard reaction?

Benzophenone reacts with phenylmagnesium bromide in ether solution to make triphenylmethanol after acid workup. Which of the following experimental mistakes will decrease the effectiveness of a Grignard reaction? 




a) the glassware was not dried before use
b) the magnesium ribbon is insoluble in ether
c) the magnesium ribbon was not wiped clean before use
d) the fume hood was too cold


Answer: a) the glassware was not dried before use
and
c) the magnesium ribbon was not wiped clean before use

Which of the following statements about semi-empirical methods are true:

Which of the following statements about semi-empirical methods are true:




a) it gives an exact solution to quantum mechanical equations
b) some experimentally measured parameters are substituted into the calculation
c) it is good at predicting structural properties that arise from subtle interactions of orbitals
d) it can be used for static molecules but not for reactions in which bonds are forming or broken


Answer: b) some experimentally measured parameters are substituted into the calculation
And
c) it is good at predicting structural properties that arise from subtle interactions of orbitals

Which of the following statements relates the value and magnitude of ΔHf to stability of a product?

Which of the following statements relates the value and magnitude of ΔHf to stability of a product?




a) a large negative value of ΔHf indicates a stable product
b) the value and magnitude of ΔHf cannot be in relation to the stability of a product
c) a large positive value of ΔHf indicates a stable product
d) a value of zero ΔHf indicates a stable product


Answer: a) a large negative value of ΔHf indicates a stable product

Which of the following statements about the ratio of products formed by a reaction under kinetic control are true?

Which of the following statements about the ratio of products formed by a reaction under kinetic control are true?




a) the ratio of products is not determined by the energies of products
b) the ratio of the products is not determined by the relative energies of transition states
c) the ratio of products is determined by the energies of products
d) the ratio of products is determined by the relative energies of the transition states


Answer: a) the ratio of products is not determined by the energies of products
And
d) the ratio of products is determined by the relative energies of the transition states

In the NaBH4 reduction of camphor:

In the NaBH4 reduction of camphor:




a. The NaBH4 reduced the carbonyl group by adding a proton (H+) to the carbonyl carbon.
b. The NaBH4 reduced the carbonyl group by adding a hydrogen atom (H) to the carbonyl carbon.
c. The NaBH4 reduced the carbonyl group by adding hydride (H:-) to the carbonyl carbon.
d. The NaBH4 provided a catalytic surface for the one step addition of a hydrogen molecule (H2) across the carbonyl double bond.
e. The NaBH4 reacted with ethanol to give (CH3CH2OH2)- which was the actual reducing agent that attacked camphor.


Answer: c. The NaBH4 reduced the carbonyl group by adding hydride (H:-) to the carbonyl carbon.

A mixture of nitric acid and sulfuric acid was added to an equimolar mixture of C6H6, C6H6Z, C6H6Y. After warming and stirring for a few minutes the nitrated products were analyzed and found to consist of the products C6H4YNO2, C6H5NO2, and C6H4ZNO2 in the ratio of 750:30:1, respectively. Which of the following can be deduced from this data?

A mixture of nitric acid and sulfuric acid was added to an equimolar mixture of C6H6, C6H6Z, C6H6Y. After warming and stirring for a few minutes the nitrated products were analyzed and found to consist of the products C6H4YNO2, C6H5NO2, and C6H4ZNO2 in the ratio of 750:30:1, respectively. Which of the following can be deduced from this data?




a. the Z group is a deactivator
b. the nitro group is a meta director
c. the Y group is a deactivator
d. benzene is the least reactive
e. the Z group is an ortho‐para director


Answer: a. the Z group is a deactivator

Which one is not a derivative of carboxylic acids?

Which one is not a derivative of carboxylic acids?




a. esters
b. carboxylic acid anhydrides
c. acid chlorides
d. amides
e. Schiff's base


Answer: e. Schiff's base

Low molecular weight esters have fruity flavors and odors. Why do esters, which have higher molecular weights than carboxylic acids, have lower boiling points than the carboxylic acids they were made from?

Low molecular weight esters have fruity flavors and odors. Why do esters, which have higher molecular weights than carboxylic acids, have lower boiling points than the carboxylic acids they were made from?




a. Carboxylic acids are solids and harder to liquify than their esters.
b. Carboxylic acids have much stronger intermolecular Van der Waals forces.
c. Most carboxylic acids exist as dimers which are held together by two hydrogen bonds.
d. Ester molecules have strong hydrogen bonding forces with other ester molecules which helps increase their volatility.
e. Boiling points of all organic esters decrease with increasing molecular weight.


Answer: c. Most carboxylic acids exist as dimers which are held together by two hydrogen bonds.

Which of the following statement(s) is/are correct?

Which of the following statement(s) is/are correct?




a. Thermodynamic control results in more stable intermediate/product being formed.
b. Thermodynamic control results in the fastest intermediate/product being formed.
c. Kinetic control results in more stable intermediate/product being formed.
d. Kinetic control results in the fastest intermediate/product being formed.
e. a and d are correct


Answer: e. a and d are correct

In the aldol condensation lab, you examined a molecular model of the aldol product, tetraphenylcyclopentadienone, TPCP. The model showed that the phenyl groups were not in the same plane as the cyclopentadienone ring or the other phenyl groups. What is the major factor preventing a planar structure from being lowest in energy?

In the aldol condensation lab, you examined a molecular model of the aldol product, tetraphenylcyclopentadienone, TPCP. The model showed that the phenyl groups were not in the same plane as the cyclopentadienone ring or the other phenyl groups. What is the major factor preventing a planar structure from being lowest in energy?




a. steric interactions between atoms on the phenyl rings when in the same plane
b. orbital overlap is reduced in the all‐planar structure
c. conjugation is maximized when the phenyls are perpendicular with the central ring
d. molecular size is reduced when they are out‐of‐plane
e. the computer can't calculate accurate structures


Answer: a. steric interactions between atoms on the phenyl rings when in the same plane

Excess ethylamine is needed in the synthesis of simazine in order to:

Excess ethylamine is needed in the synthesis of simazine in order to:




a. ensure complete nucleophilic substitution of the cyanuric chloride
b. neutralize the acid formed by the substitution reaction
c. generate the nucleophilic Cl- ion to effect the substitution reaction
d. neutralize the acidic cyanuric chloride
e. form an amine salt with the simazine product


Answer: b. neutralize the acid formed by the substitution reaction

Can we use other alcohols as a solvent for synthesis of methyl benzoate by Fischer Esterification instead of using methanol?

Can we use other alcohols as a solvent for synthesis of methyl benzoate by Fischer Esterification instead of using methanol?




a. Yes, we can because we have to add methanol anyway.
b. No, we cannot because the product will not be pure.
c. Yes, we can because other alcohols can be a good solvent.
d. No, we cannot because other alcohols cannot dissolve starting materials.
e. None of the above


Answer: b. No, we cannot because the product will not be pure.

When performing the nitration of methyl benzoate, methyl m‐nitrobenzoate was formed. It is possible to introduce a second nitro group to form the dinitrated product. This was largely avoided because:

When performing the nitration of methyl benzoate, methyl m‐nitrobenzoate was formed. It is possible to introduce a second nitro group to form the dinitrated product. This was largely avoided because:




a. the nitronium ion is not a strong enough electrophile.
b. steric hindrance would not allow a second bulky NO2 to react with the ring.
c. the reaction is carefully timed so that no dinitration is possible.
d. the nitration mixture that was used is weak and therefore highly selective.
e. the first NO2 group introduced has a strong deactivating effect so that the addition of a second group is more difficult.


Answer: e. the first NO2 group introduced has a strong deactivating effect so that the addition of a second group is more difficult.

Since indigo is highly insoluble, it must first be reduced to form a water‐soluble derivative, leucoindigo, to be used as a fabric dye. Which reagent did you use to reduce indigo?

Since indigo is highly insoluble, it must first be reduced to form a water‐soluble derivative, leucoindigo, to be used as a fabric dye. Which reagent did you use to reduce indigo?




a. 10% NaOH solution
b. 10% Na2S2O4 solution
c. 10% NaHCO3 solution
d. 10% NaCl solution
e. 5% NaOH solution


Answer: b. 10% Na2S2O4 solution

Why is UVC sunlight less dangerous to humans than UVB even if the energy of UVC radiation is higher?

Why is UVC sunlight less dangerous to humans than UVB even if the energy of UVC radiation is higher?





a. The UVC radiation is absorbed by ozone in the earth's atmosphere but UVB is not.
b. The UVC damage can be repaired by special enzymes in our body but UVB cannot.
c. UVB light can be lethal but UVC cannot.
d. There are no substances (and sunblock lotions) that absorb UVB but we have a plenty of them absorbing in UVC.
e. none of these


Answer: a. The UVC radiation is absorbed by ozone in the earth's atmosphere but UVB is not.

When a reaction is under kinetic control, the observed product ratio is controlled by:

When a reaction is under kinetic control, the observed product ratio is controlled by:





a. stabilities of the products
b. relative energies of the transition states
c. the solvent
d. the relative energy of the reactants compared to the product
e. the dynamic energy of the attacking nucleophile



Answer: b. relative energies of the transition states

The ammonium chloride solution was used in the Grignard reaction to:

The ammonium chloride solution was used in the Grignard reaction to:




a. facilitate formation of the Grignard reagent
b. hydrolyze the magnesium alkoxide to form the product alcohol
c. activate the acetone for addition to the Grignard reagent
d. moderate the reaction so it would not get too vigorous
e. convert the Grignard to a halide by SN1 substitution


Answer: b. hydrolyze the magnesium alkoxide to form the product alcohol

A purple color develops as soon as all reactants are mixed together for the aldol condensation of benzil and dibenzyl ketone. This color is due to:

A purple color develops as soon as all reactants are mixed together for the aldol condensation of benzil and dibenzyl ketone. This color is due to:





a. the production of a highly conjugated molecule.
b. decomposition of benzil.
c. the production of a reactive intermediate.
d. the presence of the carbanion of benzil.
e. decomposition of dibenzyl ketone.


Answer: a. the production of a highly conjugated molecule.

Amide bonds in living systems are hydrolyzed under _______.

Amide bonds in living systems are hydrolyzed under _______.




a. enzymatic conditions
b. acidic conditions
c. rough conditions
d. basic conditions
e. acidic and basic conditions


Answer: a. enzymatic conditions

The absorbance of a compound with a concentration 7.5 mM at 330 nm is 1.5. If the path length was 1 cm, what is the extinction coefficient of the compound at 330 nm?

The absorbance of a compound with a concentration 7.5 mM at 330 nm is 1.5. If the path length was 1 cm, what is the extinction coefficient of the compound at 330 nm? 


200 M-1 cm-1

Why are the N‐C bonds in peptides so very robust?




a. carbon and nitrogen form very strong bonds
b. they evolved to be stronger
c. they have a resonance structure which shows the peptide bonds have partial double bond character
d. they are part of large structures
e. none of these


Answer: c. they have a resonance structure which shows the peptide bonds have partial double

In the borohydride reduction of camphor, borneol is:

In the borohydride reduction of camphor, borneol is:




a. the major product because endo attack is less favorable
b. the minor product because an axial hydroxy is less stable
c. the minor product because exo attack is less favorable
d. the major product because endo attack is more favorable
e. the major product because an equatorial hydroxyl is unstable


Answer: c. the minor product because exo attack is less favorable

The grignard reagent may be viewed as a

The grignard reagent may be viewed as a




a. strong base
b. strong acid
c. weak base
d. weak acid
e. neutral reagent


Answer: a. strong base

You are trying to carry out the acid‐catalyzed esterification of benzoic acid with ethanol. Which of the following would not lead to a higher yield of the ester?

You are trying to carry out the acid‐catalyzed esterification of benzoic acid with ethanol. Which of the following would not lead to a higher yield of the ester?




a. excess ethanol
b. react benzoic acid with thionyl chloride first
c. excess benzoic acid
d. removal of water by distillation
e. removal of ethanol by distillation


Answer: e. removal of ethanol by distillation

The aldol reaction between dibenzyl ketone and benzil is synthetically useful because of which of the following?

The aldol reaction between dibenzyl ketone and benzil is synthetically useful because of which of the following?




a. The two carbonyl compounds have similar reactivity.
b. There is a large difference in the reactivity of the two compounds.
c. One of the compounds has no ‐hydrogens.
d. They are two different carbonyl compounds which is a requirement for the reaction.
e. The product crystallizes from solution and drives the reaction to completion.


Answer: c. One of the compounds has no alpha‐hydrogens.

The reaction of a Grignard reagent with an aldehyde produces a _______ alcohol and the reaction of a Grignard reagent with a ketone produces a _______ alcohol.

The reaction of a Grignard reagent with an aldehyde produces a _______ alcohol and the reaction of a Grignard reagent with a ketone produces a _______ alcohol.




a. primary, secondary
b. secondary, tertiary
c. primary, tertiary
d. primary, primary
e. tertiary, tertiary


Answer: b. secondary, tertiary

Which test is positive for all ketones?

Which test is positive for all ketones?





a. Schiff's test
b. Iodoform test
c. Tollens' test
d. Semicarbazone test
e. none of these


Answer: d. Semicarbazone test

In order to determine whether the desired product type was produced in the Grignard Reaction, you obtained an IR spectrum. The main peak that should have been absent was at approximately:

In order to determine whether the desired product type was produced in the Grignard Reaction, you obtained an IR spectrum. The main peak that should have been absent was at approximately: 





a. 2400‐2580 cm‐1
b. 3200‐3600 cm‐1
c. 1700‐1720 cm‐1
d. 3010‐3100 cm‐1
e. Fingerprint Region


Answer: c. 1700-1720 cm-1 (carbonyl is replaced with alcohol group in grignard)

The hydrolysis of esters can be done by both acid or base catalysis, however esterification of carboxylic acids can only be done by acid catalysis. Why is this?

The hydrolysis of esters can be done by both acid or base catalysis, however esterification of carboxylic acids can only be done by acid catalysis. Why is this?




a. We cannot make a strong enough base to perform the reaction.
b. Base will ruin the product produced.
c. The carboxylic acid will be deprotonated by the base and will leave an unreactive carboxylate anion.
d. The reaction can be catalyzed by base.
e. none of these


Answer: c. The carboxylic acid will be deprotonated by the base and will leave an unreactive

Why is it beneficial to use a logarithmic scale to measure pH?

Why is it beneficial to use a logarithmic scale to measure pH?



A - It is easy to calculate
B - A wider range of values can be measured
C - It is not beneficial
D - It is easy to remember


Answer: B - A wider range of values can be measured

When measuring acidity you are measuring very small values (concentrations are normally less than 1). It allows you to have more concrete measurements and associates acidity with an actual number.

Which of the following is a strong acid?

Which of the following is a strong acid?



A - CH3COO-
B - CH3COOH
C - OH-
D - HCl


Answer: D - HCl

An ACID is any sort of molecule which will donate a hydrogen ion to the solution. A STRONG acid is an acid which will dissociate completely to form an anion and a hydrogen ion.

The pH scale is a way of measuring _______.

The pH scale is a way of measuring _______.




A - Concentration
B - Acidity
C - Volume
D - Time


Answer: B - Acidity

It is measuring the concentration of hydrogen ions. Solutions with a pH of 7 are considered neutral, a pH lower than 7 is considered acidic, and a pH greater than 7 is considered basic.

The pH scale is a _______ scale.

The pH scale is a _______ scale.




A - Weight
B - Pound
C - Newton
D - Logarithmic


Answer: D - Logarithmic

A logarithmic scale is used so that a wider range of values can be measured.

Which of the following is a strong base?

Which of the following is a strong base?




A - NaOH
B - NaCl
C - NaHCO3
D - H+


Answer: A - NaOH

A BASE is any type of molecule which can accept hydrogen bonds from a solution. A STRONG base dissociates completely to form a cation and a hydroxide ion.

Which of the following is an example of diffusion?

Which of the following is an example of diffusion?



A - Salt dissolving in water without stirring
B - Cells exploding in a hypo-tonic solution
C - Precipitation of a solid from a solution
D - Water moving across a semi-permeable membrane


Answer: A - Salt dissolving in water without stirring.
DIFFUSION is the passive movement of substance from areas of higher concentration to areas of low concentration.

Which of the following is NOT true?

Which of the following is NOT true?




A - Molecules will try to move so that there is equilibrium of concentration in all parts of a solution
B - Solute molecules will move across semi-permeable membranes to equalize concentration on both sides of the membrane
C - It is impossible to have more solvent in a solution than can be found in a saturated solution of the same components
D - Diffusion and osmosis are important to biological systems


Answer: B - Solute molecules move across semi-permeable membranes to equalize concentration on both sides of the membrane
Solvent molecules move across the membrane not solute.

What would you expect to happen to a piece of celery you put into a hyper-tonic solution?

What would you expect to happen to a piece of celery you put into a hyper-tonic solution?



A - It would shrivel up
B - It would crack in half
C - It would swell
D - It would stay the same


Answer: A - it would shrivel up

HYPER-TONIC refers to a solution that has a higher concentration of solute than a particular solution. This would cause water to flow out of the cells, leaving them shriveled, so that the percentage of solute in each part would be equal.

Which of the following is responsible for swelling our hands after exercising?

Which of the following is responsible for swelling our hands after exercising?



A - Unsaturation
B - Osmosis
C - Saturation
D - Diffusion


Answer: b - Osmosis

UNSATURATED is a solution that has less than the maximum amount of solute.
SATURATED is a solution where the solvent has dissolved all of a particular solute that it can.
OSMOSIS is the process of solvent molecules (like water) moving across a semi-permeable membrane, typically active.

What do you think would happen if you added a sugar crystal to a supersaturated solution of sugar in water?

What do you think would happen if you added a sugar crystal to a supersaturated solution of sugar in water?




A - Rock candy would form; the sugar would crystallize immediately
B - Nothing; no change
C - The sugar crystal would settle on the bottom of the container in the solution
D - The sugar crystal would dissolve into the solution


Answer: A - Rock candy would form
SUPERSATURATED SOLUTIONS are those that have more dissolved solute than there would be at equilibrium for a saturated solution. They are really unstable and the solute will precipitate (crystals in this case) at the slightest provocation.

Which of the following solutes would NOT form a solution if added to water?

Which of the following solutes would NOT form a solution if added to water?



A - NH3 (ammonia)
B - NaCl (sodium chloride)
C - KCl (potassium chloride)
D - HCl (hydrogen chloride)
E - CH4 (methane)


Answer: E - CH4 (methane)


Methane is non-polar and water is polar, meaning methane cannot dissolve water. HYDROPHOBIC are non-polar molecules that cannot interact with water molecules.

Which of the following is NOT a hydrophobic substance?

Which of the following is NOT a hydrophobic substance?



A - C3H8 (propane)
B - C2H6 (ethane)
C - CH3CO2H (acetic acid)
D - C6H6 (benzene)
E - CH4 (methane)


Answer: C - CH3CO2H (acetic acid)

Acetic acid is polar, like water meaning it is not hydrophobic. HYDROPHILIC are molecules that are polar and are able to form hydrogen bonds with water molecules.

Why is solid water (ice) less dense than liquid water?

Why is solid water (ice) less dense than liquid water?



A - The hydrogen bonds between water molecules are formed and held (or frozen) farther apart than in liquid water
B - Hydrogen bonds are not able to be formed because of the cold temperature
C - Liquid water does not form hydrogen bonds
D - It is actually more dense


Answer: A - The hydrogen bonds are farther apart when frozen.


There are fewer water molecules per volume (so less mass/volume) for solid water than for liquid water. Due to the hydrogen bonds being held farther apart, and therefore occupying more volume, the overall density has decreased.

Which of the following statements accurately describe ice: I. Ice is denser than water. II. Hydrogen bonds hold ice molecules closer together than they do liquid water molecules. III. Ice has a crystalline structure.

Which of the following statements accurately describe ice:
I. Ice is denser than water. II. Hydrogen bonds hold ice molecules closer together than they do liquid water molecules. III. Ice has a crystalline structure.



A - II
B - I, II, and III
C - I
D - II and III
E - III


Answer: E - III Ice has a crystalline structure.

The hydrogen bonds in ice are different than in liquid. As a liquid hydrogen bonds are constantly being formed and breaking apart but in ice all the hydrogen bonds that are going to be made are. They are becoming more ordered and rigid, in a crystalline structure. This structure is holding them farther apart.

Which of the following concepts help explain why water can travel up a narrow tube? I. Cohesion II. Adhesion III. Specific gravity

Which of the following concepts help explain why water can travel up a narrow tube? I. Cohesion II. Adhesion III. Specific gravity



A - I, II, and III
B - I
C - II
D - I and II
E - III


Answer: D - I and II

COHESION is the action or property of like molecules sticking together, being mutually attractive (water to water).

ADHESION is the tendency of dissimilar particles or surfaces to cling to one another (water to plastic)

Water's ability to move against gravity in a narrow space, such as a tube, is called

Water's ability to move against gravity in a narrow space, such as a tube, is called



A - Hydrogen bonding
B - Osmosis
C - Capillary action
D - Cohesion



Answer: C - Capillary action

Capillary action is the ascension of liquids through a slim tube, cylinder, or permeable substance due to adhesive and cohesive forces interacting between the liquid and the surface. These together allow water to move against gravity.

Which of the following properties explain why a city near the Pacific Ocean experiences less dramatic changes in temperature during the day compared to a city farther inland? I. Water forms hydrogen bonds II. Water has a low specific heat III. Water has a high surface tension

Which of the following properties explain why a city near the Pacific Ocean experiences less dramatic changes in temperature during the day compared to a city farther inland? I. Water forms hydrogen bonds II. Water has a low specific heat III. Water has a high surface tension



A - I and II
B - II
C - III
D - I and III
E - I


Answer: E - Water forms hydrogen bonds


Land close to water is going to experience more climate change because energy is sucked in by the water in order to heat it, so extra energy is needed to heat the land. This is caused by water having a high specific heat (the energy needed to raise the temp. of 1g of a substance to 1 C)

What is an electron shell?

What is an electron shell?




A - A hard container holding electrons close to the nucleus
B - The space around the nucleus where the electrons are most likely to be found
C - The exact location of an electron
D - The electron's protective outer layer


Answer: B - The space around the nucleus where the electrons are most likely to be found


You can never know for certain where the electrons are because they are moving around, so with every snapshot you take of the atom the electrons might be in a different place. Also called electron clouds or energy levels

Which of the following statements is true?

Which of the following statements is true?




A - Electrons circle the nucleus in predictable orbits like Earth around the sun
B - Electrons can be removed from an atom to increase stability
C - Electrons travel in predictable orbits known as electron packets
D - The energy of electrons decreases with increasing distance from the nucleus



Answer: B - Electrons can be removed from an atom to increase stability

Given the following information, which element(s) are most likely to lose electrons? I. Iodine is a member of Group VII II. Strontium is located in the second column of the periodic table III. Selenium has six valence electrons

Given the following information, which element(s) are most likely to lose electrons? I. Iodine is a member of Group VII II. Strontium is located in the second column of the periodic table III. Selenium has six valence electrons




A - Iodine
B - Strontium
C - Selenium
D - Selenium and Strontium


Answer: B - Strontium


Valence electrons are the electrons that are going to interact with other atoms. Atoms without complete valence shells aspire to be Noble gases, which have full valence shells. This means that the farther the element is from the 6th row of the periodic table the less valence electrons it will have

What is the maximum number of electrons that can occupy the 2s orbital?

What is the maximum number of electrons that can occupy the 2s orbital?




A - 2
B - 3
C - 8
D - 6


Answer: A - 2
Orbitals are forms of energy levels because it too energy to move the electron to that certain orbital. The more levels you have the more energy associated with each new level because they are being pulled farther and farther away from the nucleus

What does the atomic number represent?

What does the atomic number represent?



A - Number of protons
B - Total number of electrons, protons, and neutrons
C - Number of electrons
D - Total number of electrons and protons
E - Number of neutrons


Answer: A - Number of protons

An element is defined by the number of

An element is defined by the number of



A - Neutrons
B - Ions
C - Protons
D - Electrons
E - Chemical bonds


Answer: C - Protons
This refers to the atomic number which is used to identify different elements. It all depends on how many protons are in the center because each element has a certain, different amount

Particles that are found in the atomic nucleus are

Particles that are found in the atomic nucleus are




A - Protons and electrons
B - Neutrons and electrons
C - Protons and neutrons
D - Protons, neutrons, and electrons


Answer: C - Protons and neutrons

An atomic nucleus is a collection of protons and neutrons at the center of the atom. The cluster is very small, very dense, and very positively charged

About how much of our body is made up of macro-minerals?

About how much of our body is made up of macro-minerals?




A - 4%
B - 10%
C - .001%
D - 1%
E - 25%



Answer: A - 4%

These are inorganic ionic compounds that play a role in bodily health. They include phosphorous, sulfur, and calcium.

Why is oxygen important?

Why is oxygen important?




A - We need it to participate in cellular respiration
B - it provides the "backbone " of DNA
C - It helps build strong teeth and bones
D - It creates unique bonds within and between water molecules
E - It prevents thyroid disease


Answer: A - We need it to participate in cellular respiration
Cells need a steady supply of oxygen in order to perform cellular respiration, which produces an essential molecule ATP.

What are trace elements?

What are trace elements?




A - Elements that only play a small role in our bodies
B - None are correct
C - Elements that are rare but essential
D - Elements that we only need small amounts of
E - Elements that are abundant but only found in small amounts in any given location


Answer: D - Elements that we only need in small amounts
Includes iron, iodine, copper, and zinc.

What role does carbon play in the body?

What role does carbon play in the body?




A - It forms the four bases of DNA
B - It provides the "backbone" of DNA
C - It builds large, complex molecules
D - It builds short but strong molecules
E - It produces ATP in cellular respiration


Answer: C - It builds large, complex molecules Carbon is essential to all living things, and almost all of the molecules that are made by cells are carbon-containing compounds/ Carbon builds cellular structures and carries out cellular processes

About how many years does it take for your body to replace all of its molecules?

About how many years does it take for your body to replace all of its molecules?




A - 7
B - 14
C - 1
D - 5
E - 10


Answer: A - 7
We eat and breathe because our body requires an almost constant supply of new molecules, which are used to drive our bodily processes and keep us alive

Which of the following is a definition of matter?

Which of the following is a definition of matter?




A - Anything that weighs more than ten pounds
B - Anything that has no atoms
C - None of these answers
D - Anything that has no mass
E - Anything that takes up space


Answer: E - Anything that takes up space


It includes everything we can see and cannot see (like air)

How many elements are there?

How many elements are there?



A - None of these answers
B - 200
C - 118
D - 133
E - 121


Answer: C - 118


Most occur naturally on Earth but some are created in a laboratory using nuclear processes

Which of the following is a correct definition of an element?

Which of the following is a correct definition of an element?



A - A substance with no atoms.
B - A substance with pure metal properties
C - A pure substance that can be broken down into another substance
D - A substance that cannot combine with another substance
E - A pure substance that cannot be broken down by chemical methods into simpler components


Answer: E - A pure substance that cannot be broken down into simpler components


Elements are all unique from each other, each consisting of only one type of atom. These atoms has exactly the same chemical makeup, size and mass.

Which of the following statements is true?

Which of the following statements is true?



A - Elements are the building blocks of all matter
B- Elements cannot combine together
C - Elements cannot be made in a laboratory
D - Elemental names always have two symbols written
E - All answers are true


Answer: A - Elements are the building blocks of all matter


Elements are the "ingredients" that makeup the entire world

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