question

What is the correct molecular formula of a non-cyclic alkene with n carbons? A) Cn B) CnHn C) CnH2n D) CnH2n+2

answer

C

question

What is the full name of the alkene? CH3-CH2-CH2CH=CHCH2CH3 A) Heptane B) Heptene C) 4-Heptene D) 3-Heptene

answer

D

question

What is the IUPAC name of the alkene? CH3CH(Cl)CH2CH=CHCH2CH3 A) 5-Chloro-3-heptene B) 2-Chloro-3-heptene C) 2-Chloro-4-heptene D) 2-heptenyl chloride

answer

A

question

Both 1-pentene and cylcopentane have the same molecular formula. They are A) conformers. B) not related. C) constitutional isomers.

answer

C

question

How many alkene-type constitutional isomers share the formula C6H12? A) 8 B) 9 C) 10 D) 11

answer

C

question

What is the name of a compound that has a formula of C6H10 and is a six-carbon ring? A) cyclohexane B) cyclohexene

answer

B

question

What hybridization do C=C carbons do? A) sp3 B) sp2 C) sp D) cannot be determined

answer

B

question

What is the geometry of ethylene (H2C=CH2)? A) Planar B) Linear C) Square D) Tetrahedral

answer

A

question

Describe the location of pi electron clouds (or orbital) in ethylene (H2C=CH2). A) concentrated along the line connecting the two carbon atoms. B) in the region between the two carbons, and in the common plane of all sp2 orbitals. C) in the region between the two carbons, above and below the common plane of all sp2 orbitals.

answer

C

question

To assign E,Z configuration of an alkene, priority of two substituents (or groups) on each of the two double bond carbons need to be determined. What factor determines their priority? A) Alphabetical order of their names B) Number of atoms in the groups C) The atomic number (or weight) of the first atom in each group

answer

C

question

Which is more stable? A) An alkene with two alkyl substituents on the double bond. B) A terminal alkene (with C=C at the end of the carbon chain).

answer

A

question

Read online about van der Waals radius and covalent radius, and determine which of the following statements is correct. A) A covalent radius of an atom is always greater than its van der Waals radius. B) In any molecule, the distance between two bonded atoms are much smaller than the sum of the van der Waals radii of the two atoms. C) The volume of any compounds is always larger than the sum of the volumes of its atoms in their free form (non-bonded).

answer

B

question

Select correct values for the van der Waals radius and covalent radius of hydrogen. (Search online to find their values). [1 Å (angstrom) = 10-10 meter] A) 1 Å, 1 Å B) 0.84 Å, 0.41 Å C) 1.20 Å, 2.0 Å D) 1.20 Å, 0.37 Å

answer

D

question

In section 4.7, two new concepts (nucleophile and electrophile) are introduced. Which statement is true about nucleophile and electrophile? A) A nucleophile is a Lewis acid and an electrophile is a Lewis base. B) A nucleophile is a Lewis base and an electrophile is a Lewis acid. C) There are no correlations exist between these two new concepts and Lewis acid/base.

answer

B

question

Which of the following is the strongest nucleophile? A) HO- B) H2N- C) Cl- D) F-

answer

B

question

In which of the following compounds, the proton is the strongest electrophile? A) HF B) HI C) HBr

answer

B

question

For the reaction A ? B, which of the following is the correct expression of the rate (R) of the forward reaction? A) R = [A] B) R = k[A][B] C) R = k[A]/[B] D) R = k[A]

answer

D

question

Review the Arrhenius equation which describes the relationship between chemical reaction rate constant and activation energy & reaction temperature, and determine which of the statement below is true. A) Both higher activation energy and higher temperature increase reaction rate constant. B) Higher reaction rates are associated with reactions that have lower activation energy and are run at higher temperatures. C) Both lower activation energy and lower temperature increase reaction rate constant.

answer

B

question

Between a reactant and its product, there is always a transition state that has a higher free energy than those of reactant and product. Select the correct definition of activation energy of a reaction (CHEM 106) A) the free energy of product minus the free energy of reactant. B) the free energy of product minus the free energy of the transition state. C) the free energy of transition state minus the free energy of product. D) the free energy of transition state minus the free energy of reactant.

answer

D

question

If the free energy of the product is lower than the free energy of the reactant (i.e., the starting material), is the reaction usually exothermic (heat releasing) or endothermic (heat absorbing)? A) exothermic B) endothermic

answer

A

question

A compound has a molecular formula of C7H14. Which could be a name of it? A) Methycyclohexene B) Heptane C) cycloheptane D) 1,3-heptadiene

answer

C

question

What is the name of the alkene? A) 2-Methyl-1,4-cyclohexadiene B) 1-Methyl-1,3-cyclohexadiene C) 2-Methyl-2,4-cyclohexadiene D) 1-Methyl-1,4-cyclohexadiene

answer

D

question

What is the IUPAC name of the alkene? A) 2-Chloro-5-bromo-3-heptene B) 2-Bromo-6-chloro-4-heptene C) 2-Chloro-5-bromo-4-heptene D) 5-Bromo-2-chloro-3-heptene

answer

D

question

How many pi bonds are there in a non-cyclic compound with a formula of C10H18? A) 1 B) 2 C) 3 D) 4

answer

B

question

How many constitutional isomers share the formula C5H10? A) 6 B) 7 C) 8 D) 9 E) 10

answer

E

question

Which of the following constitutional isomers is the most stable? A) CH3C(CH3)=CHCH2CH3 B) CH3C(CH3)=C(CH3)2 C) CH3CH=CHCH(CH3)2 D) CH3CH2C(CH3)=CHCH3

answer

B

question

Which of the following is vinyl bromide? A) CH3CH2Br B) H2C=CHBr C) H2C=CHCH2Br

answer

B

question

What is the geometry of the carbon skeleton of Me2C=CMe2? A) planar B) linear C) square D) tetrahedron

answer

A

question

Determine the E,Z configurations of the four compounds. (Note: no E/Z for terminal C=C bond). A) E, E, E, Z B) Z, E, E, Z C) Z, E, E, E D) Z, Z, E, Z E) Z, E, Z, Z

answer

B

question

In which of the following groups, substituents are arranged in the order of increasing priority? A) ethyl, methyl, propyl, butyl B) methyl, sec-butyl, isopropyl, vinyl C) methyl, isopropyl, sec-butyl, vinyl D) HOCH2- (hydroxymethyl), hydroxyl, amino (NH2-), chloro

answer

C

question

Which is more stable? A) A non-terminal alkene. B) A terminal alkene.

answer

A

question

Which is the more stable alkene? A) 2-pentene B) 3-pentene C) 2-methyl-1-butene D) 2-methyl-2-butene

answer

D

question

The van der Waals radius of hydrogen is more than __________ times as large as its covalent radius. A) 0.5 B) 1 C) 2 D) 3

answer

D

question

Given the energy diagram of a reaction, how many intermediates does the reaction have? A) 0 B) 1 C) 2 D) 3

answer

C

question

How many transition states does the reaction (in Q14) have? A) 0 B) 1 C) 3 D) 4

answer

D

question

Which statement is true about any nucleophile? A) Any nucleophile must be a Lewis acid. B) Any nucleophile must be a Lewis base. C) Any nucleophile must be either a Lewis base or a Lewis acid.

answer

B

question

Which of the following changes in reaction conditions will speed up a reaction? A) Adding more solvent B) Using a cooling bath C) Using a larger reaction vessel D) Wrapping the reaction flask with a heat-insulating material (assuming the rxn is exothermic)

answer

D

question

Catalysts are often used to speed up slow reactions. What does a catalyst do? A) Makes the reaction more exothermic. B) Changes the course of the reaction to have a different transition state with a lower energy. C) Makes the reaction more endothermic.

answer

B

question

Examine the energy diagrams of two reactions and determine which reaction requires a higher reaction temperature. A) Reaction A B) Reaction B

answer

A

question

Examine the energy diagrams of two reactions and determine which reaction in Q19 can proceed to completion A) Reaction A B) Reaction B

answer

B

question

In an alkene molecule, which electrons are most exposed to the outside world? A) sigma electrons in C-C single bond B) sigma electrons in C-H single bond C) pi electrons in C-C double bond D) sigma electrons in C-C double bond

answer

C

question

This chapter begins with an addition reaction of HX (hydrogen halide) to C=C in alkenes. The first step of the reaction is a Lewis acid-base reaction. Which is the Lewis acid in the addition reaction? (Be specific) A) Alkene B) HX C) proton D) pi electrons

answer

C

question

This chapter begins with an addition reaction of HX (hydrogen halide) to C=C in alkenes. The first step of the reaction is a Lewis acid-base reaction. Which is the Lewis base in the first step? A) Alkene B) HX C) proton D) pi electrons E) sigma electrons in the C=C bond

answer

D

question

In the last lecture of Chapter 4 (Alkenes), we learned that more substituted alkenes are more stable due to hyperconjugation. Hyperconjugation is A) the repulsive interaction between carbon and hydrogen nucleii B) the attractive interactions between a carbon nucleus and electrons in the sigma bond of this carbon C) the attractive interactions between a carbon nucleus and electrons in a sigma bond of its neighboring carbons

answer

C

question

In this Chapter, more substituted carbon cations are also more stable due to hyperconjugation. Is the hyperconjugation in a carbocation stronger or weaker than that in an alkene? A) Stronger, because the carbon nucleus in a carbon cation is more shielded by its valence electrons B) Stronger, because the carbon nucleus in a carbon cation is less shielded by its valence electrons C) Weaker, because the carbon nucleus in a carbon cation is more shielded by its valence electrons D) Weaker, because the carbon nucleus in a carbon cation is less shielded by its valence electrons

answer

B

question

What is true about the Markovnikov's Rule? A) It is about the regioselectivity of addition of halogen (X2) to alkenes. B) The rationale behind the rule is the stability of carbon anion intermediate. C) The rule can be justified by the stability of carbocation intermediate. D) More than one of above statements are true.

answer

C

question

What is common to the two reactions: 1. addition of HX to alkenes, and 2. acid catalyzed hydration of alkenes? A) Nothing is common to them. B) The rate determining step is common. C) Both are two-step reactions. D) The faster steps in the two reactions are same. E) B and C.

answer

E

question

For the purpose of hybridization determination, how many electron domains does a triple-bond carbon (as in an alkyne) have? A) 1 B) 2 C) 3 D) 4

answer

B

question

Section 5.10 is about addition of HX to alkynes. The first step is addition of a proton to the triple bond to form a carbocation. How many electron clouds does the cationic carbon have? A) 1 B) 2 C) 3 D) 4

answer

B

question

Addition of two molecules of HBr to an alkene molecule gives dibromoalkane(s). How many dibromo products are expected for the reaction of two different alkynes: 1-butyne and 2-butyne? A) one dibromo product in each case. B) one from 1-butyne and two from 2-butyne. C) two dibromo products in each case. D) one from 1-butyne and three from 2-butyne.

answer

B

question

How many products are formed from acid-catalyzed addition of H2O to a terminal alkyne? A) 1 B) 2 C) 3 D) 4

answer

A

question

How many products are formed from acid-catalyzed addition of H2O to an internal alkyne? A) 1 B) 2 C) 3 D) 4

answer

B

question

How many isomeric products are produced from Pt-catalyzed addition of H2 to cis-1,2-dimethycyclopentene? (Section 5.12) A) 1 B) 2 C) 3 D) 4

answer

A

question

PKa values of alkanes, alkenes, and terminal alkynes are >60, 44, and 25, respectively. Which is the most acidic? A) butane B) 1-butene C) 1-butyne

answer

C

question

What is an acetylide anion? A)The anion of acetic acid. B) The reaction product of a terminal alkyne and a strong base (e.g., NaNH2) C) The anion of acetone.

answer

B

question

What can you make in one step with an acetylide anion as a reagent? A) acetic acid. B) an alkane. C) an alkyne. D) an alkene.

answer

C

question

What is the product of the reaction of acetylide anion and 1-bromo-2-methylbutane? A) 2-Methyl-hex-1-yne. B) 3-Methyl-hex-1-yne. C) 1-Methyl-hex-1-yne. D) 5-Methyl-hex-1-yne. E) None of above.

answer

E

question

Which procedure will lead to a ketone? A) 1. acetylide anion + an alkyl bromide; 2. Pt catalyzed hydrogenation of step 1 product. B) 1. acetylide anion + an alkyl bromide; 2. hydration of step 1 product. C) 1. acetylide anion + an alkyl bromide; 2. step 1 product + HBr. D) 1. acetylide anion + an alkyl bromide; 2. Hydrogenation of step 1 product using Lindlar catalyst.

answer

B

question

The cationic polymerization of isobutene can be initiated by A) -OH B) a strong Bronsted-Lowry acid

answer

B

question

A free radical contains at least one atom that A) has an empty orbital. B) has an unpaired electron. C) carries a positive charge. D) carries a negative charge.

answer

B

question

What will be the major product of the reaction of 2-methyl-2-butene with HBr? A) 2-Bromo-3-methyl-butane B) 3-Bromo-3-methyl-butane C) 3-Bromo-2-methyl-butane D) 2-Bromo-2-methyl-butane

answer

D

question

What will be the major product of the reaction of 2-methyl-1-butene with HBr? A) 2-Bromo-3-methyl-butane B) 3-Bromo-3-methyl-butane C) 3-Bromo-2-methyl-butane D) 2-Bromo-2-methyl-butane

answer

D

question

What is the product of acid catalyzed addition of water to 1-methylcyclohexene? A) 2-Methyl-cyclohexanol. B) 3-Methyl-cyclohexanol. C) 1-Methyl-cyclohexanol. D) 4-Methyl-cyclohexanol.

answer

C

question

Is the first step in the addition of HX to alkenes the rate determining step? A) Yes B) No

answer

A

question

Which of the following names are wrong? a. 4-ethyl-2-pentyne b. 1-bromo-4-heptyne c. 2-methyl-3-hexyne d. 3-pentyne A) None of them B) all except c C) a and b D) c and d

answer

B

question

What is the product of the reaction of 1 mole of propyne with 2 mole of HBr? A) acetone B) 2,2-dibromopropane C) 1,2-dibromopropane D) 1,3-dibromopropane

answer

B

question

How many major dibromo products are expected for the reaction of 2-pentyne and excess HBr? A) 1 B) 2 C) 3 D) 4

answer

B

question

What is the name of the tautomer of pent-1-en-2-ol? A) pent-1-en-3-ol B) Pentan-2-one (a ketone) C) pent-2-en-3-ol

answer

B

question

What is the name of the product of Pt-catalyzed addition of H2 to cis-1,2-dimethycyclopentene? A) trans-1,2-dimethycyclopentene. B) cis-1,2-dimethycyclopentane C) trans-1,2-dimethycyclopentane

answer

B

question

What is the product of reaction of 2-butyne with excess H2 in presence of Pt/C? A) Butane. B) cis-2-Butene C) trans-2-Butene D) 2-butanone (a ketone)

answer

A

question

Beside acetylide anion, what else do you need to make 5-methylhex-1-yne in one reaction? A) 1-Bromo-3-methyl-butane. B) 5-Bromo-hexane. C) 1-Bromo-2-methyl-butane. D) 1-Bromo-4-methyl-butane.

answer

A

question

What is the product of the reaction of acetylide anion and 1-bromo-2-methylbutane? A) 2-Methyl-hex-1-yne. B) 3-Methyl-hex-1-yne. C) 1-Methyl-hex-1-yne. D) 5-Methyl-hex-1-yne. E) None of above

answer

E

question

Rank the carbocations in the order of increasing stability. A) a < b < c < d B) d < c < a < b C) d < a < c < b D) d < b < c < a

answer

B

question

Which is the correct structure of the monomer used to synthesize the polymer (polystyrene)? A) a B) b C) c D) d

answer

D

question

Which is the correct structure of the monomer used to synthesize Teflon? A) a B) b C) c D) d

answer

A

question

A cis-alkene is also called a(n) A) (Z)-alkene B) (E)-alkene

answer

A

question

Which of the following categories of compounds have cis-trans isomerism? a. Linear alkanes, b. Alkenes, c. Alkynes, d. Cycloalkanes A) a,b,c,d B) b,c C) b,d D) c,d

answer

C

question

Which of the following names are not right? a. trans-cyclobutene b. trans-1-ethyl-1-methyl-cyclohexane c. cis-2-butene d. trans-2-methyl-2-pentene A) all of them B) only one of them C) only two of them D) a,b,d E) b,c,d

answer

D

question

Every hand is chiral. How about the object in the image (two hands closed)? A) it is still chiral. B) It is no longer chiral.

answer

B

question

A carbon atom that has four different substituents is a stereocenter (or simply a chiral carbon). How many stereocenters are in the three compounds? A) 2, 1, 2 B) 2, 1, 3 C) 1, 1, 3 D) 1, 1, 2

answer

B

question

Compounds that are mirror images of each other are called A) cis,trans-isomers B) constitutional isomers C) conformers D) meso compounds E) enantiomers

answer

E

question

These two structures A) are different representation of the same compound. B) are enantiomers. C) constitutional isomers. D) conformers.

answer

A

question

A chiral carbon can have one of the two configurations: R and S. To determine its configuration, the first thing is to assign priority to its four substituents. The rule for priority assignment is same as that used for priority assignment of C=C substituents. Assign priorities for the four groups below (1: highest priority, 4: lowest): H, methyl, hydroxyl, -COOH A) 1, 2, 3, 4 B) 4, 3, 2, 1 C) 4, 2, 3, 1 D) 4, 3, 1, 2

answer

D

question

(continuing on Q8). To determine R/S configuration of a chiral carbon, the next step is to orient the molecule so that #4 is directed away from you. If #1, #2 and #3 go clockwise, the chiral center has A) a R configuration. B) an S configuration.

answer

A

question

If you are given the name of a chiral compound and need to figure out the R/S configuration, the first thing to do is to draw a 3D structure of the compound. What convention is followed in drawing a 3D representation of molecule for the purpose of R/S determination? A) Two thin solid lines for bonds in the plane perpendicular to the paper, a wedge for the bond that is on the left, and a dashed wedge (or line) for a bond that is on the right. B) Two thin solid lines for bonds in the back, a wedge for the bond that is above the plane and on the left, and a dashed wedge (or line) for a bond that is below (behind) the plane and on the right. C) Two thin solid lines for bonds in the plane of paper, a dashed wedge for the bond that is above the plane, and a solid wedge (or line) for a bond that is below (behind) the plane. D) Two thin solid lines for bonds in the plane of paper, a solid wedge for the bond that is above the plane, and a dashed wedge (or line) for a bond that is below (behind) the plane.

answer

D

question

In all three 3D structures, the #4 group is directed away from you, which makes R/S assignment straight forward. What are their configurations? A) S, R, S. B) R, R, R. C) S, S, S. D) S, R, R.

answer

D

question

If the #4 group in a 3D drawing of a chiral molecule is not in the back, you can switch the #4 group with the group in the back, then apply the R/S definition. If you get R, then the molecule has an S configuration. Now, use this technique to determine the configuration of the molecule shown. A) R B) S

answer

B

question

If the #4 group is not in the back, you can use another technique to determine R/S: First assign priority to each group, then reposition your eyes in such a way, so that the #4 is on the other side (away from your eyes). Then you can apply the R/S definition. Use this technique to determine R/S configuration of the structure shown. A) R B) S

answer

A

question

If the #4 group is not in the back, but is at the base of the tetrahedron, there is a third technique to use to determine R/S: hold the vertical bond and turn the structure to make #4 group move to where the dashed bond is (You may need to redraw the structure). Then you can apply the R/S definition. Use this technique to determine R/S configuration of the structure shown. A) R B) S

answer

B

question

The electromagnetic wave of light has two components. (Google: Electromagnetic radiation Wiki) They are A) electric and acoustic B) electric and magnetic C) magnetic and acoustic D) water wave and sound wave

answer

B

question

What does a polarizer do to a beam of light? A)It acts like a filter which only allows lightwaves with electric wave oriented in certain direction to pass through. B) It acts an attenuator that reduces intensities of all lightwaves in the beam of light.

answer

A

question

After passing a polarizer, the light is called polarized light. A solution of chiral compound can cause the direction of the electric wave component of the polarized light to rotate. Use of another polarizer (called analyzer) will let you know how much the light has rotated. The rotation angle depends on A) the nature of the molecule. B) the concentration of the solution C) the length of the solution D) the wavelength of light E) all of above F) only three of A-D.

answer

E

question

A solution is known to be a mixture of a chiral compound and its isomer. If the solution does not rotate a polarized light, what can be said about the isomer? A) The isomer is likely a constitutional isomer. B) The isomer is likely an enantiomer. (In other words, the solution is a racemic mixture - lecture slide 15) C) The isomer is likely a meso compound (which has an even # of chiral centers, and a symmetry plane (i.e., the molecule is symmetric)

answer

B

question

These two compounds are A) cis-trans isomers. B) constitutional isomers. C) enantiomers. D) diastereomers. E) not related.

answer

B

question

These two compounds are A) cis-trans isomers. B) constitutional isomers. C) enantiomers. D) identical. E) not related.

answer

D

question

Which of the following names must be wrong or incomplete? a. trans-cyclopentene b. trans-1-ethyl-1-methyl-cyclopentane c. trans-3-ethyl-3-hexene d. cis-2-butene A) only one of them B) only two of them C) three of them D) all of them

answer

C

question

Which compounds are achiral? A) a B) b C) c D) all three E) two of them

answer

E

question

A carbon atom that has four different substituents is a stereocenter (or simply a chiral carbon). How many stereocenters are in the three compounds? A) 2, 1, 2 B) 2, 1, 3 C) 1, 1, 3 D) 1, 1, 2

answer

B

question

Which pairs are enantiomers? A) a B) b C) c D) all three E) two of them F) none of them

answer

F

question

These two structures A) are different representation of the same compound. B) are enantiomers. C) constitutional isomers. D) conformers.

answer

A

question

Assign priorities for the four groups below (1: highest priority, 4: lowest): Vinyl (-C=C), propyl, hydroxyl, -COOH A) 1, 2, 3, 4 B) 3, 4, 1, 2 C) 4, 2, 3, 1 D) 4, 3, 1, 2

answer

B

question

In the reactions of cis-2-butene with each of the following reagents, which will lead to a mixture of isomeric products? 1. HCl 2. CH3OH + acid 3. H2, Pt/C A) 1, 2, 3 B) 3 C) 1, 2 D) 2, 3

answer

C

question

How many stereoisomers are possible for CH3CH=CHCH(OH)CH3? A) 1 B) 2 C) 3 D) 4

answer

D

question

The rind of lemon contains a considerable amount of (R)-(+)-limonene. What does "+" mean? A) It means that there is a cis C=C bond. B) It means that there is a trans C=C bond. C) It means that the stereoisomer rotates light clockwise. D) It means that the stereoisomer rotates light counterclockwise.

answer

C

question

A solution of chiral compound can cause the direction of the electric wave component of the polarized light to rotate. If the molar concentration of the solution is fixed, which of the following parameters DOES NOT affect the rotation angle? A) the nature of the molecule. B) the diameter of sample tube. C) the length of the solution D) the wavelength of light

answer

B

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