Question 1

Which of the following statements best describes the inductive effect in organic molecules?

Accepted Answer

It is the polarization of electron density in sigma bonds towards more electronegative atoms or groups.

Question 2

Which of the following carbocations is most stabilized by hyperconjugation?

Accepted Answer

Isopropyl cation $(CH_3)_2CH^+$

Question 3

Which effect is primarily responsible for the stabilization of the negative charge in the acetate ion $CH_3COO^-$?

Accepted Answer

Mesomeric (resonance) effect

Question 4

Which of the following compounds is expected to be the most acidic?

Accepted Answer

Acetic acid $CH_3COOH$

Question 5

Why does the acidity of alcohols increase when electron-withdrawing groups are attached to the carbon bearing the hydroxyl group?

Accepted Answer

They increase the stability of the conjugate base by delocalizing the negative charge.

Question 6

Which of the following is the correct order of acidity for the following compounds: ethanesulfonic acid, acetic acid, ethanol?

Accepted Answer

$CH_3CH_2SO_3H > CH_3COOH > CH_3CH_2OH$

Question 7

Which of the following statements about resonance structures is FALSE?

Accepted Answer

Resonance structures can have different numbers of electrons.

Question 8

Which of the following factors increases the basicity of an amine?

Accepted Answer

Attachment of electron-donating alkyl groups to the nitrogen atom.

Question 9

Which of the following is the correct order of stability for carbocations?

Accepted Answer

Tertiary $>$ Secondary $>$ Primary $>$ Methyl

Question 10

Which of the following best explains why thiols ($RSH$) are more acidic than alcohols ($ROH$)?

Accepted Answer

Sulfur has a larger atomic size, which stabilizes the negative charge on the conjugate base.

Question 11

Which of the following compounds will have the highest basicity?

Accepted Answer

Triethylamine $(C_2H_5)_3N$

Question 12

Which of the following is a correct statement about the effect of hybridization on the basicity of nitrogen?

Accepted Answer

Nitrogen in an sp3 hybrid orbital is more basic than in an sp2 orbital.

Question 13

Which of the following functional groups is the least acidic?

Accepted Answer

Alkanes $R-CH_3$

Question 14

Which of the following statements about the mesomeric effect is TRUE?

Accepted Answer

It stabilizes both cations and anions by delocalizing charge over a molecule.

Question 15

Which of the following is the strongest acid?

Accepted Answer

Sulfonic acid $R-SO_3H$

Question 16

Which of the following will decrease the basicity of an amine?

Accepted Answer

Attachment of a nitro group ($-NO_2$) to the aromatic ring.

Question 17

Which of the following is the correct order of acidity for the following hydrogen-containing compounds: $H_2O$, $ROH$, $RSH$?

Accepted Answer

$H_2O > ROH > RSH$

Question 18

Which of the following is the most stable resonance contributor for a molecule?

Accepted Answer

The structure with complete octets and charges on the most electronegative atoms.

Question 19

Which of the following statements about the effect of atomic size on acidity is correct?

Accepted Answer

Larger atomic size stabilizes the negative charge on the conjugate base, increasing acidity.

Electron Displacement Effects in Organic Molecules: Inductive Effect, Hyperconjugation, and Mesomeric Effect

Study Guide - Practice Questions