Question 1

Which of the following statements best describes a Lewis acid?

Accepted Answer

A substance that accepts a pair of electrons.

Question 2

Which of the following pairs are conjugate acid-base pairs in the reaction: $$ \mathrm{NH_3$ + H_2O \rightarrow NH_4$^+ + OH^-} $$?

Accepted Answer

$$ \mathrm{NH_3$} $$ and $$ \mathrm{NH_4$^+} $$

Question 3

Which factor most increases the acidity of a molecule?

Accepted Answer

Increasing the size of the atom bonded to hydrogen.

Question 4

Given the following compounds, which is the strongest acid? $$ \mathrm{CH_3COOH} $$, $$ \mathrm{CH_3CH_2OH} $$, $$ \mathrm{H_2O} $$, $$ \mathrm{NH_3$} $$

Accepted Answer

$$ \mathrm{CH_3COOH} $$

Question 5

Which of the following best describes the relationship between $$ K_a $$ and $$ pK_a $$?

Accepted Answer

$$ pK_a = -\log_{10}(K_a) $$

Question 6

Which of the following is a correct statement about the boiling points of alkanes?

Accepted Answer

Boiling point increases with increased molecular weight.

Question 7

Which conformation of butane is the most stable?

Accepted Answer

Anti conformation

Question 8

In the chair conformation of methylcyclohexane, which position is favored for the methyl group and why?

Accepted Answer

Equatorial, because it minimizes steric strain.

Question 9

Which of the following pairs are constitutional isomers?

Accepted Answer

1-butanol and 2-butanol

Question 10

Which of the following molecules is chiral?

Accepted Answer

2-butanol

Question 11

Assign the configuration (R or S) to the chiral center in (R)-2-bromobutane.

Accepted Answer

R

Question 12

Which of the following best describes a meso compound?

Accepted Answer

A compound with chiral centers and a plane of symmetry, making it achiral.

Question 13

Which of the following is a Lewis base in the reaction: $$ \mathrm{BF_3$ + NH_3$ \rightarrow F_3B-NH_3$} $$?

Accepted Answer

$$ \mathrm{NH_3$} $$

Question 14

Which of the following statements about enantiomers is correct?

Accepted Answer

They have identical physical properties except for their interaction with plane-polarized light.

Question 15

Which of the following factors will increase the acidity of a carboxylic acid?

Accepted Answer

Adding an electron-withdrawing group to the alpha carbon.

Question 16

Which of the following best describes the difference between a Bronsted-Lowry acid and a Lewis acid?

Accepted Answer

A Bronsted-Lowry acid donates a proton, while a Lewis acid accepts a pair of electrons.

Question 17

Which of the following is NOT a factor that influences acid strength?

Accepted Answer

Molar mass

Question 18

Which of the following is true about the stability of chair conformations of cyclohexane?

Accepted Answer

The conformation with more equatorial substituents is more stable.

Question 19

Which of the following best describes a nucleophile?

Accepted Answer

An electron pair donor

Question 20

Which of the following is a diastereomer of (2R,3R)-2,3-dibromobutane?

Accepted Answer

(2S,3R)-2,3-dibromobutane

Acid/Base Chemistry, Conformational Analysis, and Stereochemistry: Study Guide

Guida di studio - Domande di pratica

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