Orbitals, Alcohols and Benzene: Chemistry Connections Quiz

Question 1

In phenol, which statement best describes the carbon atom bonded directly to the hydroxyl group?

Accepted Answer

It is sp2-hybridized as part of the aromatic ring

Answer

It is sp3-hybridized because it forms a C–O single bond

Answer

It is sp-hybridized due to resonance with oxygen

Answer

Its hybridization alternates between sp2 and sp3

Question 2

Why is cyclohexanol significantly less acidic than phenol?

Accepted Answer

Phenoxide ion is resonance-stabilized, while cyclohexanolate is not

Answer

Cyclohexanol has a stronger O–H bond because its oxygen is sp-hybridized

Answer

Cyclohexanol cannot form hydrogen bonds in water

Answer

Phenol contains fewer lone pairs on oxygen than cyclohexanol

Question 3

Which molecule contains a carbon atom that is sp-hybridized?

Accepted Answer

Ethyne

Answer

Ethanol

Answer

Benzene

Answer

Cyclohexanol

Question 4

Benzene undergoes electrophilic substitution more readily than electrophilic addition mainly because substitution

Accepted Answer

retains aromatic stabilization in the final product

Answer

produces a more polar intermediate

Answer

occurs without any catalyst

Answer

converts all carbon atoms to sp3 hybridization

Question 5

When ethanol is dehydrated to ethene, the two carbon atoms in the product are

Accepted Answer

both sp2-hybridized

Answer

both sp3-hybridized

Answer

one sp2-hybridized and one sp3-hybridized

Answer

both sp-hybridized

Question 6

Which reagent is commonly used to distinguish phenol from ethanol by giving a visible color change with phenol?

Accepted Answer

Neutral ferric chloride solution

Answer

Sodium chloride solution

Answer

Dilute hydrochloric acid

Answer

Aqueous sodium nitrate

Question 7

The approximately 120° bond angles around each carbon atom in benzene are most consistent with which hybridization?

Accepted Answer

sp2

Answer

sp3

Answer

sp

Answer

dsp2

Question 8

Which alcohol is expected to oxidize directly to a ketone under typical mild oxidation conditions?

Accepted Answer

Propan-2-ol

Answer

Methanol

Answer

Ethanol

Answer

2-methylpropan-2-ol

Question 9

Why is the C–O bond in phenol shorter than the C–O bond in cyclohexanol?

Accepted Answer

The phenolic oxygen participates in resonance with the ring

Answer

Phenol has a heavier carbon atom attached to oxygen

Answer

Cyclohexanol contains an sp carbon attached to oxygen

Answer

Phenol has no lone pairs on oxygen in solution

Question 10

Which set correctly matches the dominant hybridization of carbon atoms in benzene, ethanol, and ethyne, respectively?

Accepted Answer

sp2, sp3, sp

Answer

sp3, sp2, sp

Answer

sp, sp3, sp2

Answer

sp2, sp, sp3

Question 11

Compared with benzene, why is phenol more reactive toward electrophilic substitution?

Accepted Answer

The –OH group donates electron density into the ring by resonance

Answer

The –OH group withdraws electron density strongly by induction only

Answer

Phenol is non-aromatic in the neutral state

Answer

The oxygen atom forces the ring carbons to become sp3-hybridized

Question 12

Which statement best explains why tertiary alcohols are generally resistant to oxidation under ordinary conditions?

Accepted Answer

They lack a hydrogen on the carbon bearing the –OH group

Answer

Their oxygen atoms cannot donate lone pairs

Answer

They contain carbon-carbon triple bonds

Answer

They are always aromatic compounds

Question 13

In anisole, the carbon of the methoxy methyl group is

Accepted Answer

sp3-hybridized

Answer

sp-hybridized

Answer

sp2-hybridized because it is attached to oxygen

Answer

unhybridized

Question 14

Which compound would be least soluble in water at room temperature?

Accepted Answer

Benzene

Answer

Methanol

Answer

Ethanol

Answer

Phenol

Question 15

During nitration of benzene, the species that acts as the electrophile is

Accepted Answer

NO2+

Answer

NO3−

Answer

SO3

Answer

NH4+

Question 16

Which statement about the oxygen atom in a simple alcohol such as ethanol is most accurate?

Accepted Answer

It is commonly described as approximately sp3-hybridized with two lone pairs

Answer

It is sp-hybridized because it forms two sigma bonds

Answer

It is forced to be sp2-hybridized by the alkyl group

Answer

It has no hybrid orbitals because oxygen cannot hybridize

Question 17

If benzene is hydrogenated completely to cyclohexane, the hybridization of each ring carbon changes from

Accepted Answer

sp2 to sp3

Answer

sp to sp2

Answer

sp3 to sp2

Answer

sp to sp3

Question 18

Which pair of compounds are constitutional isomers with the molecular formula C2H6O?

Accepted Answer

Ethanol and dimethyl ether

Answer

Phenol and cyclohexanone

Answer

Ethyne and ethene

Answer

Benzene and cyclohexene

Question 19

Why does benzene show equal C–C bond lengths rather than alternating single and double bond lengths?

Accepted Answer

Its pi electrons are delocalized over the entire ring

Answer

The ring rapidly flips between chair conformations

Answer

Each carbon uses only sp3 orbitals for bonding

Answer

The molecule contains three isolated double bonds

Question 20

Which alcohol would most readily form a stable tertiary carbocation during substitution with concentrated hydrochloric acid?

Accepted Answer

2-methylpropan-2-ol

Answer

Ethanol

Answer

Propan-1-ol

Answer

Ethane-1,2-diol

Orbitals, Alcohols and Benzene: Chemistry Connections Quiz

Create a competition