lab exam 237 questions

Solvent

Mobile Phase

Glass plastic or aluminum plate

Solid Back

For the Distillation and GC Experiment: The difference in the fractions will be based on the temperature of the vapor/liquid

True

For the Kinetics Experiment: Your product will be __________

a racemic mixture

For the Phase Transfer Catalysis Experiment: The phase transfer catalyst for the reaction is...

benzyl tri-n-butylammonium chloride

Distillation separates compounds on the basis of....

boiling point

Acetanilide is a(n)....

oxidant

You are allowed to use your cell phone during lab.

false

When venting your separatory funnel, direct the spout at the hood.

true

You should only ever plug the heating mantle into the variac.

true

Silica Gel or alumina

Stationary phase

For the TLC Experiment: The ideal solvent system carries the compounds to the top of the TLC plate.

false

For the Kinetics Experiment: A reaction that has two molecules involved at the rate determining step normally has an overall reaction order equal to....

2

For the Kinetics Experiment: Which of the following is the rate determining step for the reaction?

formation of the carbocation

A strong peak is defined by having an absorbance value greater than 50%

False

For the Distillation and GC Experiment: It is easier to separate liquids that have boiling points within a range of 5 degrees than it is liquids that have boiling points within a range of 10 degrees

False

For the Phase Transfer Catalysis Experiment: Allyl bromide is soluble in the aqueous phase

False

If your skin comes into contact with the sulfuric/phosphoric acid mixture, which of the following should you do?

Wash the affected area with cold water Let your TA know Wash the affected area with sodium bicarbonate solution

If an irritant makes contact with your skin, which of the following actions should you take?

Wash the area with water Alert your TA

Which of the following forms of electromagnetic radiation has the longest wavelength?

infrared

For the Distillation and GC Experiment: Which of the following processes occur during a distillation?

collecting the condensate condensing a vapor vaporizing a liquid

For the Extraction Experiment: Which physical property of liquids determines which layer is on the top or bottom?

density

For the TLC Experiment: Ethyl acetate is a non-polar solvent.

false

When equilibrating between conformations of cyclohexane (a chair-flip), axial substituents trade places and stay as axial substituents.

false

For the Phase Transfer Catalysis Experiment: When running a TLC plate, what is the correct order of compounds from bottom to the top?

least polar compounds, medium polar compounds, most polar compounds

For the Extraction Experiment: After benzocaine is mixed with sodium hydroxide, it will be _______ and soluble in the ________.

neutral, organic layer

Which of the following are representations of organic molecules?

plastic models skeletal structures computational models

Which of the following is not among the standard conformations of butane?

semi-eclipsed

For the Distillation and GC Experiment: The _______ the number of theoretical plates, the _______ the separation of a mixture of two liquids

smaller, better larger, worse

When working with DCM, you should be aware of which of the following issues?

You should not wear gold jewelry when working with DCM When it makes contact with your skin, it will discolor the affected area When it makes contact with your skin, you will feel a cold burn

For the Dehydration of Cyclohexanol Experiment: Alcohols can....

act as a base

For the Kinetics Experiment: When a solution containing bromothymol blue is acidic, it is.....

yellow

Spectroscopy is the instrumental processes by which information about molecular structure is obtained through analysis of the molecule's __________ of electromagnetic radiation.

emission scattering absorption

For the Recrystallization Experiment: As compared to pure compounds, impure compounds...

have a melting point that encompasses a wider temperature range

For the Distillation and GC Experiment: The placement of the thermocouple should be....

in the neck of the distillation head just below the collection well

For the Recrystallization Experiment: Which of the following is a negative aspect of the method of recrystallization?

incompatible with oils

For the Recrystallization Experiment: Recrystallization is a suitable method for purifying...

liquids of high volatility

For the TLC Experiment: Compounds that have the _____ affinity for the stationary phase and _____ affinity for the mobile phase will travel the furthest.

lowest, greatest

For the Extraction Experiment: After benzoic acid is mixed with hydrochloric acid, it will be _______ and soluble in the ________.

neutral, organic layer

For the TLC Experiment: The distance traveled by a compound depends on....

polarity of the compound

For the Dehydration of Cyclohexanol Experiment: According the Le Chatelier's Principle, in order to shift the equilibrium towards the product side, we can...

remove the product add more reactant

If you spill some ethyl acetate on your hand, you should...

remove your glove and replace it with a new one.

Which of the following are possible vibrations associated with water?

scissoring asymmetric stretching symmetric stretching

For the TLC Experiment: Chromatography is a technique that is used to ________ different compounds

separate

For the Recrystallization Experiment: The sample is dissolved in hot solvent then filtered while hot. The filtrate is allowed to cool and the mixture is filtered a second time. What effect will result if the filtrate solution is cooled too rapidly?

small impure crystals will form

For the Phase Transfer Catalysis Experiment: The method of purifying the result of this reaction is...

Extraction Column Chromatography

For the Dehydration of Cyclohexanol Experiment: What are the qualitative tests being performed during this experiment?

Infrared spectroscopy Baeyer's test bromine test

If your skin comes into contact with a chemical, you should rinse the affected area for 15 minutes under running water.

true

In order to apply silicone oil/grease to a glass joint, use your fingers to smear the grease on the smaller part of the joint.

False

For the IR Experiment: During this week's experiment, you will be working with a program called....

IR Tutor

What does it mean if a compound (like 1-chloro-1-phenylethane) is a lachrymator?

It can cause tears (like liquid droplets, not rips) to form in your eye It is an irritant

The Molecular mechanics model substitutes springs for bonds and balls for atoms

True

For the Extraction Experiment: Typically salts will be soluble in the aqueous phase.

true

Which region of an IR spectrum is considered the "fingerprint" region?

1500 to 400 cm-1

For the Kinetics Experiment: Which solvent mixture is the "most" polar?

40% ethanol - 60% water

Beaker or bottle with solvent

TLC Chamber

Computational chemistry calculates physical and chemical properties of compounds based upon _________________.

Theory and Oberservation

TLC spotters are capillary tubes and so they should be disposed of in the....

glass waste

The placement of the thermocouple should be....

in the neck of the distillation head just below the collection well

For the Extraction Experiment: Typically organic compounds will be soluble in the organic phase.

true

An SN1 reaction is...

Unimolecular Nucleophilic Substitution

For the Dehydration of Cyclohexanol Experiment: Which of the following is the worst leaving group?

-OH

The different geometries that a molecule can attain by bond rotations and bends are called conformations.

True

For the Recrystallization Experiment: Which of the following techniques are used in this experiment?

Vacuum Filtration Recrystallization

If your skin comes into contact with the potassium permanganate solution, which of the following should you do?

Wash the affected area with water Let your TA know

For the Phase Transfer Catalysis Experiment: The reaction in this experiment is....

a Williamson Ether Synthesis a Nucleophilic Substitution

For the Recrystallization Experiment: The melting point of a pure compound is typically....

a temperature range of 1 - 2 degrees Celsius

When using an IR spectrometer, the first thing you should do is....

add our sample to the plate

Infrared spectroscopy is particularly good at detecting functional groups such as...

aldehyde groups ester groups