OC-2019 Flashcards by potatochips ~

Which of the following compounds has an Ionic bond?
I. H2O
II. NH4Cl
III. CH3Cl
IV. CH3Li

A. II
B. IV
C. I
D. III

electronegativity > 1.7 = ionic

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How many hydrogen atoms are in one molecule of propene?
A. 4
B. 3
C. 6
D. 8

CnH2n

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In which species are all the carbon atoms considered to be sp2 hybridized?
l. C2H2
II. C2H4
Ill. C3H8
IV. C4H10

A. IV
B. Il
C. I
D. Ill

Sp3 - alkane
sp2 - alkene
sp - alkyne

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How many different compounds have the formula C5H12?
A. 5
B. 2
C. 4
D. 3

C5H12 - 3
C4H10O - 4

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In which species Is the carbon-nitrogen bond the shortest?
I. CH3NH2
II. CH2NH
Ill. (CH3)4N+
IV. CH3CN

A. Il
B. I
C. IV
D. Ill

Bond Order = Bond Strength = 1/Bond Length
Bond length is inversely proportional to the bond order

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What Is the hybridization of the carbon atom in a carboxyl group?
A. sp
B. sp3
C. sp2
D. dsp3

sp2

Carboxyl - C double bond O
Sp2 = alkene

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Functional Group:
Alcohol
Ether
Amine
Aldehyde
Ketone
Carboxylic Acid
Ester
Amide

REVIEW!!

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Which of the following hydrocarbon has the lowest boiling point?
l. C4H10
ll. CH4
Ill. C6H6
IV. C2H6

A. IV
B. II
C. I
D. III

higher C atoms/cyclic = high BP
high molecular weight = high IMF = high BP

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How many different alcohols have the molecular formula C4H10O?
A. 2
B. 4
C. 3
D. 5

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Which compound Is expected to be most soluble in water at 25oC
I. N2 (g)
II. O2 (g)
Ill (C2H5)2NH (l)
IV. C2H5OC2H5 (l)

A. III
B. IV
C. I
D. II

III

Protic [-OH, -NH, -FH]
Aprotic [-O, -N, -F]
Non-polar [O2, N2, CH4]

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The gentle oxidation of ethanol (CH3CH2OH) produces ______
A. ethanal, CH3CHO
B. ethanoic acid, CH3CO2H
C. carbon monoxide, CO
D. carbon dioxide, CO2

ethanal

primary alcohol -> aldehyde -> carboxylic acid
secondary alcohol –> ketone
tertiary alcohol –> no reaction

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The following compounds have very similar molar masses. What would be the correct order when they
are arranged in order of increasing strength of their intermolecular forces.
l. C3H8
Il. CH3OCH3
III. CH3CH2OH

A. II < I < III
B. III < I < II
C. I < II < III
D. III < II < I

I < II < III

Intermolecular Forces: HB > Dipole-dipole > Van der Waals

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What is the position of the bromine atom relative to the methyl group in 3-bromotoluene?
A. meta
B. para
C. ortho
D. trans

meta

mono –> 1
ortho –> 1, 2
meta –> 1, 3
para —> 1, 4

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Which combination of reactants produces an ester?
A. aldehyde and potassium permanganate
B. acid and alcohol
C. acid and aldehyde
D. alcohol and aldehyde

acid and alcohol

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In crystallization, the solution which is obtained after filtration is the
A. clear solution
B. colloidal solution
C. suspended solution
D. None of the given answers

clear solution

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In crystallization, the crystal phases can be Inter-converted by varying ______
A. temperature
B. pressure
C. viscosity
D. size

temperature

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Which separation technique is based in the volatility of the compounds to be separated?
A. solvent extraction
B. distillation
C. paper chromatography
D. filtration

distillation

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Fractional distillation is different from distillation because of the presence of a _______
A. Fractionating column
B. Condenser
C. Conical flask
D. Distillation flask

Fractionating column

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A common measure of efficiency in a fractionating column is the
A. length of the condenser used in the setup
B. number of distillation types
C. number of components in the solution
D. number of theoretical plates in the column

number of theoretical plates in the column

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Five grams an organic solid was dissolved in 100 mL of distilled water. Which of the following extraction
methods can remove the largest amount of organic solid from an aqueous solution?
A. Extract the aqueous solution with a 150-mL portion of ether.
B. Extract the aqueous solution with three 50-mL portions of ether.
C. Extract the aqueous solution with a 150-mL portion of acetic acid.
D. Extract the aqueous solution with three 50-mL portions of acetic acid.

Extract the aqueous solution with three 50-mL portions of ether.

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Which of the following funnels should be used to filter hot mother liquor during recrystallization?
A. Buchner funnel
B. Hirsch funnel
C. Long stem funnel
D. Short stem funnel

Short stem funnel

short stem/stem less - hot gravity filtration
buschner funnel - suction/vacuum filtration

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What is the key step in a recrystallization process?
A Taking the melting point of wet crystals
B. Dissolving the solid in a large quantity of cold solvent
C. Allowing the hot solution to cool slowly and let crystals grow
D. Removing the soluble impurities by vacuum filtration

Allowing the hot solution to cool slowly and let crystals grow

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Which of the following is the example of crystallization process?
A. Purification of alum
B. None of the given answers
C. Separation of gases from air
D. Purification of sea water

Purification of alum

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A constant boiling mixture of two in a solution is called a/an _______
A. azeotrope
B. Ideal
C. non-ideal solution
D. eutectic mixture

azeotrope

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A compound Is known to decompose at its boiling point. Which of the following can be to purity this substance? A. Steam distillation B. Fractional distillation C. Liquid-liquid extraction D. Vacuum distillation

Steam distillation

Which is the INCORRECT statement among the following? A. An impure sample of the substance has a different melting point. B. Two different pure substances have the same melting points. C. Melting point serves as the criterion of purity of a solid substance. D. Every pure crystalline substance has a characteristic and unique melting point.

Two different pure substances have the same melting points.

The boiling point of a liquid is the temperature at which the vapor pressure is ______ A. lesser than internal pressure B. equal to internal pressure C. equal to external pressure D. greater than internal pressure

equal to external pressure (usually atmospheric pressure pressure)

Which of the following statements is correct? A. Solid reactants can be weighed directly in the weighing pan of the analytical balance B. Weight of liquids is approximately equal to its density. C. Solid reactants can be transferred to a reaction flask by using a metal spatula. D. Volatile liquids can be weighed by getting the mass of the empty vial with cap first.

Volatile liquids can be weighed by getting the mass of the empty vial with cap first.

A reaction mixture needs to be cooled to -77•C after refluxing. What Is the best method to be used? A. Place the reaction vessel in an ice bath. B. Place the reaction vessel in the freezer. C. Place the reaction vessel in a salt and crushed ice mixture. D. Place tie reaction mixture in a dry ice-acetone mixture.

Place tie reaction mixture in a dry ice-acetone mixture. • Ice bath: 0°C (maximum) • Freezer: -20°C • Salt and crushed ice mixture: -20°C

Which of reactions will consume the most oxygen? A. complete combustion one mole of octane B. complete combustion of one mole of 2,3-dimethylhexane C. complete combustion of one mole of 2,3,4-trimethylpentane D. All the given compounds win consume the same amount of oxygen.

All the given compounds win consume the same amount of oxygen. (Determine the molecular formula of each compound and compare)

Which of the following techniques can be used to heat a reaction to 200•C? A. Use a Bunsen burner to heat the reaction vessel. B. use a heating mantle with stirring. C. Place the reaction vessel in a sand bath with stirring. D. Place the reaction vessel in a water bath with stirring.

Place the reaction vessel in a sand bath with stirring.

Which alkyl halide will most likely undergo SN2 mechanism? A. 2-bromobutane B. bromomethane C. 2-bromo-2-methylpropane D. 1-bromobutane

bromomethane ## Footnote 1. tertiary & secondary (SN1) 2. primary (SN2) less carbon = less hindrance

Aldehydes and ketones generally react by ______ A. nucleophilic substitution B. nucleophilic addition C. electrophile addition D. electrophile substitution

nucleophilic addition

AICl3 is a catalyst used in the alkylation of aromatic compounds. It is a A. a Lewis acid B. a Lowry-Bronsted acid C. an Arrhenius acid D. a Lewis base

a Lewis acid

The reaction rate is defined as the rate at concentration of the reactants ______ time or the rate at which the concentration of products _______ with time A. decrease, decrease B. Increase, Increase C. decrease, Increase D. Increase. decrease

decrease, Increase

Hydrogenation of an alkene yields _______ A. alcohol B. aldehyde C. alkane D. alkyne

C. alkane

Which of following Is produced when hydrogen is reacted with 2-butanone? A. tertiary B. aldehyde C. primary alcohol D. secondary alcohol

secondary alcohol ## Footnote secondary alcohol --> ketone

What of the following reactions are favored by polar aprotic solvent? A. Both SN1 and SN2 reactions B. SN1 reactions C. None of the given choices D. SN2 reactions

SN2 reactions

Quantitative analysis of compounds can be done using A. Ion exchange chromatography B. Liquid chromatography C. Gas chromatography D. Thin layer chromatography

Gas chromatography

A mobile phase can be classified as I. Solid Il. Liquid Ill. Gas A. Il only B. Ill C. Il and Ill only D. I only

Il and Ill only

The ion exchange resin with a functional group of HSO3- exchanges ions with _____ A. Small cations and anions B. Cations C. Large cations and anions D. Anions

Cations

In thin layer chromatography, the solvent or mobile phase contained in a closed chamber is a mixture of A. a liquid and a gas B. liquid C. solids D. gases

liquid

. The chromaplate or thin layer chromatography plate is made up of A. Wood B. Fibro C. Metal D. Glass

Glass

Affinity chromatography Is used for the analysis and isolation of ______ A. All of the given answer B. Insoluble starch substances C. Enzyme tyrosinase D. Antibodies bound with a covalently-attached antigen on cellulose column

All of the given answer

Retardation the ratio of A. Distance moved by solvent from base line to distance moved by the substance from base line B. Distance moved by substance from base line to distance moved by the solvent from base line C. Distance moved by solvent from top fine to distance moved by the substance from top line D. Distance moved by substance from top line to distance moved by the solvent from top line

Distance moved by substance from base line to distance moved by the solvent from base line substance --> solvent

Gas-solid chromatography is ______ chromatography as basic principle Involved. A. Absorption B. Adsorption C. Ion-exchange D. Exclusion

Adsorption

In chromatography, the relative solubility of solute in both the phases determines the _____ A. Rate of disappearance of solute B. Rate of movement of solvent C. Rate of disappearance of solvent D. Rate of movement of solute

Rate of movement of solute

Which of the following chromatographic methods is most suitable for the analysis of high molecular weight compounds that are soluble in non-polar solvents? A. gas- liquid B. gel filtration C. ion-exchange D. gel permeation

gel permeation “HIGH MOLECULAR WEIGHT” = SIZE exclusion gas-liquid: for low molecular weight volatile compounds gel filtration: more commonly used for biological macromolecules

In thin layer chromatography, the relative adsorption of components of the mixture is expressed in terms of its _______ A. Retardation factor B. Solubility factor C. Acceleration factor D. Both acceleration end retardation factor

Retardation factor

Column chromatography is based on the principle of A. Ion-exchange B. Differential adsorption C. Absorption D. Exclusion principle

Differential adsorption

The components of the in-column chromatography are eluted in order of A. Increasing polarity end decreasing distribution ratio B. Decreasing polarity and increasing distribution ratio C. Increasing polarity and Increasing distribution ratio D. Decreasing polarity and decreasing distribution ratio

Increasing polarity and Increasing distribution ratio

Benzene has a smaller distribution ratio, D, In squalene than cyclohexane. squalene is an aliphatic type of hydrocarbon. What is the order of elution of the two compounds from the GC column? A. Benzene will be eluted first B. Cyclohexane will be eluted first. C. The order of elution cannot be determined. D. The two peaks will overlap.

Benzene will be eluted first

The elution power of a solvent is determined by A. Its overall polarity B. The polarity of the stationary phase C. All of the given answers D. The nature of the sample components

All of the given answers

What the wavelength range for UV spectrum of light? A. 400 nm - 700 nm B. 10 nm to 400 nm C. 700 nm to 1 mm D. 0.01 nm to 10 nm

10 nm to 400 nm

Which is the correct statement from the following? A. Molecular spectra is more complicated than atomic spectra B. Molecular spectra arises from the transition of an electron between molecular energy levels C. In molecular transitions. electronic, rotational and vibration transitions occurs D. All of the given choices

All of the given choices

Alcohol and ether are often used as solvents. What Is the disadvantage of using these to dissolve analytes for spectroscopic analysis in the UV-visible region? A. They react with the analyte given the energy at this region. B. Their solvents prevent the analyte from absorbing light. C. They also absorb light at the UV-visible region. D. They interfere in the transition of the electrons of the analyte

They interfere in the transition of the electrons of the analyte

longest wavelength max in its UV Spectrum

1. Conjugated: more conjugated double bonds = longer wavelength 2. electron donating group: -OH, -OCH?, and -NH? can increase wavelength

Which of the following is a NOT a characteristic of chromophores? A. May contain extensive conjugated double bonds B. Contains unsaturated functional group C. Added to ions that do not strongly absorb light in the UV-visible region D. Absorbs strongly at 800 nm

Added to ions that do not strongly absorb light in the UV-visible region

Which of the following Is an application of molecular spectroscopy? A. All of the given answers B. Basis of understanding of colors C. Structural investigation D. Study of energetically excited reaction products

All of the given answers

Formula of C7H14O exhibits an IR peak at 1715 cm-1. The compound may be a/an ____ A. ketone B. ether C. ester D. alcohol

ketone The IR peak at 1715 cm?¹ indicates a carbonyl group.

0. At which region can be found the peaks due to N — H, C — H and O — H stretching and bending motions? A. 2500 to 2000 cm-1 B. 1500 to 1000 cm-1 C. 4000 to 2500 cm-1 D. 2000 to 1500 cm-1

4000 to 2500 cm-1

Hazardous wastes by defining may be all of the following EXCEPT ______ A. Explosive B. Toxic C. Corrosive D. Reactive

Explosive

Which treatment method is NOT typically used to remove organic compounds? A. Thermal B. Biological C. Physical D. Chemical

Thermal

The following are requirements for hazardous waste storage EXCEPT A. The floors should be impermeable liquids and resistant to attack by chemicals. B. Drums should be preferably stored upright or pallets and stacked no more than four drums C. The facility should be enclosed but ventilated. D. The facility should be properly secured and can be easily accessed by anyone.

The facility should be properly secured and can be easily accessed by anyone.

. Waste solvents which are halogenated should be placed in separate containers from non-halogenated waste solvents because ______. A. Non-halogenated waste solvents are more toxic. B. They are not compatible with each other. C. They will react with each other. D. The cost to properly dispose halogenated waste solvents is higher

The cost to properly dispose halogenated waste solvents is higher

All of the following about hazardous waste containers are true, EXCEPT for the following A. Containers must be closed except when removing or adding waste. B. Any type of container, Including food containers. can be used to contain hazardous waste. C. Contents must be compatible with the type of waste containers. D. Containers must be clean on the outside.

Any type of container, Including food containers. can be used to contain hazardous waste.

Segregation of waste organic solvents is very important because _______ A The costs for disposal of waste solvents differ. B. Some waste solvents can still be recycled. C. Waste solvents differ in proper treatment. D: All of the given answers

All of the given answers

Which method is considered an unacceptable means of disposing waste? A. All methods given are unacceptable B. Pouring down the sink C. Placing in the regular trash D. Pouring down the drainage canal

All methods given are unacceptable

If you discover that a hazardous waste container has a minor leak. what should you do? A. Patch the leaking hazardous waste container. B. Place the leaking container on to a secondary container so that the waste will be property collected until It is removed from the laboratory. C. Immediately transfer the hazardous waste to another empty container in good condition. D. Immediately notify the Pollution Control Officer so that an environmental report may be filed with the regulatory agency.

Immediately transfer the hazardous waste to another empty container in good condition.

How is clean, unbroken or broken glass waste to be disposed of? A. Into a cardboard box lined with a black bag and taped. For small quantities of broken glass. put into sharps container B. Into containers lined with black bags C. Into containers lined with yellow bags. D. Into containers lined with clear bags

A. Into a cardboard box lined with a black bag and taped. For small quantities of broken glass. put into sharps container

. When a chemical splashes In the eye, rinse for ______ A. 10 seconds B. 30 seconds C. 5 minutes D. 15 minutes

15 minutes

Which is the correct procedure for mixing acid and water? A. Pour acid into water B. Pour them at the same time C. Pour water into acid D. Let the supervisor pour them

Pour acid into water

Which of the following is an acceptable practice when working in a chemical laboratory? A. Wearing a laboratory coat and safety goggles while performing the analysis B. Wearing sandals or open-toed shoes C. Eating and drinking inside the chemical laboratory D. Wearing gloves to touch door handles, elevator buttons, etc.

Wearing a laboratory coat and safety goggles while performing the analysis

Which of the following pair is not correct about NFPA diamond chemical label hazard warning? A. Blue: 0 highly toxic B. Blue: health C. Red: flammability D. Red: 0 non-flammable

Blue: 0 highly toxic ## Footnote [Blue: "0" means no hazard, not "highly toxic]

. Flammable liquids burn only when their vapor is mixed with air in the appropriate concentration. When handling flammable liquids, you should _______ A avoid nearby sources of ignition B. use adequately ventilated work areas C. keep containers closed except during transfer of Contents D. minimize the creation of flammable vapors

minimize the creation of flammable vapors

Organic peroxides are particularly dangerous when ________ A. concentrated B. all of the above C. when ethyl ether or tetrahydrofuran is left open to the air md allowed to evaporate D. heated

all of the above