question

What role does AIBN play in this polymerization?

answer

initiator

question

What are the three steps (in order) of the mechanism for this experiment's polymerization?

answer

Initiation, propagation, termination

question

When drawing reaction mechanisms, a ______________________ arrow is used to show the movement of a single electron.

answer

Fishhook

question

Where can you find a copy of the course syllabus that covers many things including policies concerning excused absences, grade determination and an outline for writing lab reports?

answer

On the main Course Content page of Blackboard for this course.

question

You are preparing poly(methyl methacrylate), also called PMMA. What is the commercial name of this polymer?

answer

Plexiglas

question

The viscosity of the reaction mixture will ______________________ as polymerization progresses.

answer

Increase

question

After thoroughly washing with water the polymer you produce today, you will be allowed to take it home. Should you ever take home chemicals from lab without permission?

answer

no

question

How many points are deducted per business day for late lab reports?

answer

3 points

question

Methyl methacrylate is _____________________ and toxic. This polymerization must be performed _____________________.

answer

Flammable, in the hood

question

According to the experimental procedure, you should check the status of your reaction vial every ______________________.

answer

10 minutes

question

Which of the following structures is the final product of the first step in the following reaction? quiz 3, intermediate.gif

answer

structure b

question

Hydroboration (the addition of borane to an alkene) is a(n) _______________________ reaction.

answer

Reduction

question

Why are highly concentrated solutions of hydrogen peroxide dangerous? (Select all that apply)

answer

a. Highly concentrated solutions of peroxides can blister the skin. b. Highly concentrated solutions of peroxides can be explosive! c. Highly concentrated solutions of peroxides are caustic.

question

Dr. Herbert Charles Brown developed an effective route for the synthesis of which chemical used in CHEM 3106 Experiment 1, "Catalytic Hydrogenation of an Alkene: Octane"?

answer

Sodium borohydride

question

Configuration is ________________ in the oxidation step of the above reaction.

answer

retained

question

Organoboranes have become an attractive pathway for the preparation of which of the following?

answer

a. Alcohols b. Alkanes c. Amines d. Organohalides °ALL OF THE ABOVE

question

The four-centered transition state of the hydroboration step is shown below. This is a concerted addition reaction meaning all the bonds are being made or broken at the same time. This mechanism is characteristic of a group of reactions called ____________________ reactions.

answer

Pericyclic

question

Why are alkylboranes not generally isolated out of solution?

answer

They are pyrophoric

question

The net result of the reaction below involves addition of H and OH across a double bond. This hydroboration/oxidation allows the -OH group to add to the least substituted carbon. What is this type of addition called?

answer

anti-Markovnikov addition

question

Which acts at the active reagent in hydroboration?

answer

the monomer? or The dimer (B2H6)

question

The Diels-Alder reaction is reversible.

answer

true

question

Calculate the percent yield of the reaction below using the given information. 0.10 g Cmpd A + 0.040 g Cmpd B -> 0.070 g Cmpd C MW Compound A = 200 g/mol MW Compound B = 100 g/mol MW Compound C = 300 g/mol

answer

...

question

According to the lab manual, the first step in any filtration is:

answer

Wet the filter paper with the solvent being used

question

What does the "s" refer to in the term "s-cis conformation" of the diene?

answer

The single bond connecting the two double bonds

question

What causes the bubbles to form in the polymerization of poly(methyl methacrylate), PMMA?

answer

Evolution of nitrogen gas from AIBN

question

With what combination of electron-withdrawing and electron-donating groups can you speed up a Diels-Alder reaction?

answer

If the dienophile bears electron-withdrawing groups and the diene bears electron-donating groups

question

When should you remove the rubber tubing from the filter flask?

answer

Before turning the water off

question

The Diels-Alder reaction is pericyclic meaning bonds are forming and breaking around the ring at the same time. What reaction have you performed this semester that is pericyclic?

answer

Hydroboration

question

This experiment's reaction combines a conjugated diene with an alkene (dienophile). What is the addition product of this reaction often called?

answer

Adduct

question

What are some benefits of using a powder drying agent such as magnesium sulfate? (Select all that apply)

answer

c. Increased rate of drying e. High surface area

question

When setting up this experiment's reaction, you should:

answer

. Use a capped vial and recap it between addition of each reagent

question

What technique will you use to monitor the progress of the Friedel-Crafts acylation of ferrocene?

answer

TLC

question

The cyclopentadienyl anion has chemistry similar to what well known aromatic ring compound?

answer

benzene

question

Which of the following chemicals is the missing reagent in the reaction below? quiz 5, reaction0.gif

answer

Acetyl chloride

question

This experiment requires the use of a needle and syringe. Which of the following statements is true based on the needle/syringe policy in the CHEM 3105 and 3106 courses?

answer

TAs will properly uncap all needles; students should not uncap or recap any needle.

question

Match the "side effect" with the correct type of reaction.

answer

Polyalkylation A. Friedel-Crafts Alkylation Ring deactivation B. Friedel-Crafts Acylation Ring activation A. Friedel-Crafts Alkylation Rearrangement of the intermediate carbocation A. Friedel-Crafts Alkylation Resonance stabilization of the acylium cation B. Friedel-Crafts Acylation

question

You were supposed to calculate the percent yield of the product from the Diels-Alder experiment. Is the following statement true or false: "1 g of anthracene plus 1 g of maleic anhydride should produce 2 g of the Diels-Alder adduct."

answer

false

question

What two reagents used in this experiment are moisture sensitive & irritants? (These chemicals should be dispensed in the hood and always recapped after use.)

answer

a. Aluminum chloride c. Acetyl chloride

question

Friedel-Crafts alkylations and acylations are catalyzed by _________________________.

answer

lewis acids

question

Match the types of phases in column chromatography:

answer

Stationary phase A.Solid phase Mobile phase B. Liquid phase alumina/silica A. Solid phase solvent B. Liquid phase

question

Why do you adjust the solvent system used to elute your products?

answer

Nonpolar solvents, like hexane, will increase the amount of time a nonpolar product, like ferrocene, spends in the mobile phase. To elute polar products, like diacetylferrocene, a more polar solvent system, like a methanol/dichloromethane mixture, needs to be used.

question

Match the letter with the correct column component as described in your prior reading section. You will use one option twice. (NOTE: the experimental procedure says another component should be added instead of B. Match that component as well.)

answer

A D. Solvent B C. Sand C A. Alumina D C. Sand E B. Glass wool/cotton plug Instead of B (see note above) E. Product-alumina mixture and alumina

question

The following scenario and calculations are meant to give you practice for the procedure & calculations you are required to do for this lab report. In this scenario, you started with 100 mg of ferrocene and then obtained 100 mg of crude product from Experiment 5's reaction. Experiment 6's procedure requires that you dissolve your crude product in 0.5 mL of CH2Cl2 and then mix it with 300 mg of alumina. According to the lab manual, if the crude product is greater than 75 mg, you're only supposed to add half of the alumina/product mixture. You isolate 11 mg of ferrocene, 25 mg of acetylferrocene, and 13 mg of diacetylferrocene from your column. Fill in the blanks for the missing values (remember significant figures) in the equations below.

answer

Specified Answer for: x1 .011 Specified Answer for: x2 .075 Specified Answer for: x3 .025 Specified Answer for: x4 .013 Specified Answer for: x5 0.22 Specified Answer for: x6 0.096

question

Order the components of the crude product mixture in order of increasing polarity (least polar to most polar) as it pertains to column chromatography (not dipoles). Hint - this is the order the products will elute from the column.

answer

ferrocene (2), acetylferrocene (3), diacetylferrocene (1)

question

One of the major differences between column chromatography and TLC is that the mobile phase __________________ in column chromatography and the mobile phase __________________ in TLC.

answer

Descends, ascends

question

When using multiple elution solvents, the _______________________ solvent in which the material is readily soluble should be used to add the sample to the column.

answer

least polar

question

Solvent that elutes from the column is collected in a series of ________________________.

answer

fractions

question

Use the flowchart from your lab manual (shown below and on page 225 of your lab manual) to answer the following question. What type of compound could your unknown be if it is insoluble in water, insoluble in 5% NaOH, and soluble in 5% HCl?

answer

1°, 2°, or 3° Amine with more than 8 carbons or an aromatic amine

question

Is it likely that an aliphatic compound with 14 carbons be soluble in water?

answer

no

question

Are "negative" results useful when attempting to classify an unknown organic compound?

answer

yes

question

What safety precautions should you take while testing the odor of an unknown compound? (Select all that apply)

answer

b. Gently waft the vapor toward you c. Wear goggles d. Keep the sample several inches away from the nose

question

Use the flowchart from your lab manual (shown below and on page 225 of your lab manual) to answer the following question. What type of compound could your unknown be if it is soluble in water, tests basic to litmus paper, and is soluble in ether?

answer

...

question

A common phrase to remember when considering the solubility of a compound is _____________________.

answer

like dissolves like

question

How can you test the solubility of a liquid sample?

answer

Add a few drops of the liquid unknown to 0.5 mL solvent in a shell vial or test tube

question

How does a column chromatography column relate to a distillation column?

answer

The longer the column, the greater the separation of sample components.

question

Which of the following changes blue litmus to red ?

answer

phenols

question

There is no sharp dividing line between soluble and insoluble, however the manual suggests that to be considered soluble how many milligrams must dissolve in half a milliliter of solvent?

answer

15 mg

question

If you are careful you can use the color of your compound as an identification clue. Structures of the colored organic compounds stated in Experiment 7 (p 222) are shown below as well as the structure of salicylic acid for comparison as a colorless compound. Based on these structures, select which of the following is/are chromophore(s) that can cause organic compounds to be colored. (Select all that apply)

answer

a. The amino group b. Extended conjugation in a molecule

question

What functional group(s) is/are likely to be present in your unknown if you observe the following classification test results: No precipitate was formed after performing the 2,4-DNP test A red coloration from the Ceric Nitrate Test A blue-green coloration from the Jones Oxidation Formation of cloudiness after 5 minutes from the Lucas Test

answer

A secondary alcohol

question

What functional group(s) is/are likely to be present in your unknown if you observe the following classification test results: Formation of a red precipitate after performing the 2,4-DNP test Formation of a silver mirror after performing the Tollens Test Formation of a green precipitate after 80 seconds from the Chromic Acid Test

answer

aromatic aldehyde

question

Of the functional groups that you are testing for in lab experiment 8 which are basic?

answer

amines

question

What safety precautions should you take while performing the classifications tests for an unknown compound? (Select all that apply)

answer

b. Wear goggles c. Wear gloves d. Always securely recap bottles after use

question

Why is the 2,4-dinitrophenylhydrazine test a good test to run if you do not think the unknown is an amine?

answer

This is a rapid test and can be done early to eliminate several possibilities.

question

Which functional group can spontaneously form explosive peroxides and should be tested frequently and handled carefully?

answer

ethers

question

The lab manual states that there is one solvent in which all of the unknowns are soluble. What solvent is this?

answer

ethanol

question

Bromine water is used to test for the presence of electron rich aromatic rings. What hazards are associated with the use of bromine?

answer

Bromine is highly toxic and can cause severe burns

question

You should obtain an IR spectrum of your unknown before you performed the classification tests. You will use the classification tests to confirm you interpretation of the IR spectrum. What is the IR frequency range for the carbonyl functional group as stated in the lab manual?

answer

1675-1840 cm-1

question

What functional group(s) is/are likely to be present in your unknown if you observe the following classification test results: A blue-green coloration from the Copper Ion Test An insoluble precipitate forms after performing the Hinsberg test Decolorization of the bromine solution in the Bromine Water Test

answer

A primary or secondary amine that contains an aromatic group

question

What gases evolve during the preparation of an acid chloride? Note - this reaction should be performed in the hood.

answer

Hydrogen chloride, carbon dioxide, carbon monoxide

question

Which reagent used in one of the preparation of derivatives procedures tends to hydrolyze to form a carboxylic acid and must be checked for purity before use?

answer

3,5-Dinitrobenzoyl chloride

question

Your derivative has an observed melting point range of 137-140. According to the table below, which compound is your unknown?

answer

Propenoic acid

question

Why must an alcohol be anhydrous when synthesizing its derivative using an isocyanate?

answer

Falsely high melting points may be obtained for the product, Unwanted byproducts will be produced, Water can hydrolyze the isocyanate

question

Even though modern chemists can readily identify unknowns by various _____________________, the old fashioned solubility tests, classification tests, and preparation of derivatives can serve as a useful learning tool for new students.

answer

Spectral analyses

question

Which physical property of the prepared derivative is used to help identify your unknown?

answer

Melting point

question

You think your liquid unknown may be propenoic acid or propanoic acid. According to the table below, what are the boiling points of propenoic and propanoic acids?

answer

Propenoic acid - 141 °C; Propanoic acid - 141 °C

question

Your lab manual says, "Look at the blue notebook of possible unknowns and choose the derivative that gives the largest difference in melting points between your list of possibilities; make that derivative." According to the table below, which derivative should you prepare to determine if your unknown is either propenoic acid or propanoic acid?

answer

The p-toluidide derivative of a carboxylic acid

question

What should you do with a reaction vial in order to prevent loss of product?

answer

Place it in a small beaker to prevent tipping

question

What properties of Grignard reagents give them their strong nucleophilic character? (Select all that apply)

answer

c. The carbanionic character at carbon e. The highly polarized carbon-metal bond

question

Alumina/silica gel Solvent

answer

Stationary phase Mobile phase

question

In organic chemistry, what does the term "wet" mean?

answer

a material that contains water

question

The Grignard reagent you will use in this experiment is commercially available. You will not need to prepare the reagent, but understanding how to prepare this kind of reagent is still important. Why is ether, a relatively nonpolar solvent, key in the synthesis of Grignard reagents?

answer

Ether will complex with the magnesium in the Grignard reagent to increase its solubility in the nonpolar solvent

question

Grignard reactions are unique in organic synthesis because a new carbon-carbon single bond is formed; a ____________________ nucleophile attacks a ____________________ electrophile. Which compound contains the nucleophile and which contains the electrophile?

answer

Carbon (from the Grignard reagent), carbon (from the carbonyl compound)

question

During the isolation step of this experiment, the ether layer is on bottom.

answer

false

question

You are going to perform a "name reaction" in this experiment, the Grignard reaction, shown below. Which chemical in this Grignard reaction is the Grignard reagent?

answer

Phenylmagnesium chloride

question

There is more than one route by which esters can be synthesized. Which route will be used in the procedure for this specific experiment (Experiment 3106-11)?

answer

Esterification of a carboxylic acid with an alcohol in the presence of an acid catalyst

question

What are high molecular weight (contains chains up to 36 carbons long), naturally occurring esters of fatty acids called?

answer

waxes

question

You should always smell new and unknown compounds.

answer

false

question

Your TA will dispense the sulfuric acid in the hood. What two specific things should you do if concentrated H2SO4 spilled onto your skin?

answer

b. Wash the area for at least 15 min (in the safety shower if necessary) c. Notify your TA

question

Esterification is a nonreversible process.

answer

false

question

According to the lab manual, hydrogenation of oils on a large scale is referred to as?

answer

Hardening

question

How many -OH groups are present in glycerol?

answer

3

question

The type of esterification in the procedure for this specific experiment (Experiment 3106-12) is also known as _______________________.

answer

Fischer Esterification

question

What is combinatorial chemistry?

answer

Performing the same reaction with different reactants to get a library of products

question

Fats that contain a cis-alkene group are also called _______________________.

answer

unsaturated fats

question

What interaction makes the Nylon polymer so strong?

answer

Hydrogen bonding between the C=O and N-H groups

question

Acid halides react with atmospheric water to produce what compound?

answer

The corresponding carboxylic acid

question

Lachrymators should only be used and/or produced in the hood because they can irritate your eyes and make them tear up.

answer

true

question

During the industrial synthesis of Nylon-6,6, what compound is formed before the formation of the product?

answer

The corresponding amine salt of 1,6-hexandiamine

question

What does the "6,6" refer to in the name Nylon-6,6?

answer

The number of carbons in each of the two comonomers

question

You will synthesize Nylon-6,6 in a beaker containing an organic phase (cyclohexane) and an aqueous phase (water). Where does the polymerization reaction occur?

answer

At the interface of the aqueous and organic layers

question

What natural product mentioned in the lab manual gains strength by a similar interaction as that exhibited in Nylon?

answer

Silk fibers

question

What intermediary compound will be synthesized in this experiment before the formation of the product?

answer

The corresponding acid chloride of adipic acid

question

What functional group is present in Nylon-6,6?

answer

amide

question

There are several methods described in the lab manual to trap gases that can be produced by organic reactions. The reactions performed in this experiment do produce three byproduct gases. These reactions will be performed in the hood to prevent gas from accumulating in the lab. What are the three byproduct gases that are produced in the acid chloride step of this reaction?

answer

Carbon dioxide, carbon monoxide, and hydrochloric acid

question

Acetone can react with sodium borohydride.

answer

true

question

Which term can be used to describe the addition of hydrogen to an alkene?

answer

saturation

question

The H-H bond is _______________________ when molecular hydrogen is adsorbed by a metal.

answer

weakened

question

A sample on a chromatographic column is subjected to which two opposing forces?

answer

c. its solubility in the elution solvent system d. its adsorption to the solid phase

question

An extraction solvent should be __________________ the solution solvent.

answer

immiscible with

question

After adding the sodium borohydride reagent, the balloon should stay inflated for at least ______________________.

answer

30 min

question

Which compound will strongly adsorb to the silver nitrate/silica gel stationary phase?

answer

octene

question

Refer to the SDS of pentane (search online for "pentane SDS" or "pentane MSDS"). Find pentane's density (also called specific gravity). Water's density is 1.0 g/mL. Is pentane more or less dense than water? Does this mean it will be the top layer or bottom layer in an extraction with water?

answer

less dense, top layer

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