Question 1

Which of the following statements best explains why the O-H bond in a carboxylic acid is more acidic than the C-H bond?

Accepted Answer

Oxygen is more electronegative than carbon, stabilizing the negative charge on the conjugate base.

Question 2

Given the following acids: acetic acid ($pK_a = 4.76$), methyl alcohol ($pK_a = 15.5$), and methylamine ($pK_a = 40$), which is the strongest acid and why?

Accepted Answer

Acetic acid, because it has the lowest $pK_a$ value.

Question 3

What is the hybridization and bond angle of the central carbon in $CO_2$?

Accepted Answer

sp hybridization, $180^	ext{o}$ bond angle

Question 4

Which factor most increases the acidity of a hydrogen atom attached to a central atom as you move down a group in the periodic table?

Accepted Answer

Increasing atomic size of the central atom

Question 5

A buffer solution is best described as:

Accepted Answer

A solution containing a weak acid and its conjugate base

Question 6

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

Accepted Answer

$pK_a = -\log K_a$

Question 7

If a carboxylic acid is placed in a solution with a pH much higher than its $pK_a$, what will be the predominant form?

Accepted Answer

The deprotonated (charged) form, $RCOO^-$

Question 8

Which of the following is a correct application of the Henderson-Hasselbalch equation?

Accepted Answer

$\mathrm{pH} = pK_a + \log \left( \frac{[A^-]}{[HA]} \right)$

Question 9

Which of the following statements about acid-base equilibrium is correct?

Accepted Answer

The equilibrium favors formation of the weaker acid.

Question 10

Which of the following best explains why carboxylic acids are stronger acids than alcohols?

Accepted Answer

Carboxylic acids have resonance stabilization and inductive electron withdrawal.

Question 11

Which of the following is a Lewis acid?

Accepted Answer

A species that accepts a share in an electron pair

Question 12

Which of the following factors does NOT increase the strength of an acid?

Accepted Answer

Decreasing electronegativity of the atom attached to the acidic proton

Question 13

Which of the following compounds will be neutral in its acidic form and charged in its basic form?

Accepted Answer

Carboxylic acid

Question 14

What is the hybridization of the oxygen atom in the hydroxyl group of a carboxylic acid?

Accepted Answer

sp$^3$

Question 15

Which of the following statements about the effect of substituents on acid strength is correct?

Accepted Answer

The closer an electronegative substituent is to the acidic proton, the stronger the acid.

Question 16

Which of the following is the correct order of increasing acidity for the following compounds: $CH_4$, $NH_3$, $H_2O$, $HF$?

Accepted Answer

$CH_4 < NH_3 < H_2O < HF$

Question 17

Which of the following is true about the behavior of alcohols in acid-base reactions?

Accepted Answer

Alcohols can act as both acids and bases depending on the reaction conditions.

Question 18

If the $pH$ of a solution is 3 and the $pK_a$ of a compound is 5, what is the predominant form of the compound?

Accepted Answer

The protonated (acidic) form

Question 19

Which of the following best describes the effect of hybridization on acidity?

Accepted Answer

Higher s-character in the hybrid orbital increases acidity.

Organic Chemistry Study Notes: Hybridization, Electronegativity, and Acids & Bases (Ch. 1 Part 2 & Ch. 2 Part 1)

Study Guide - Practice Questions

Study Guide - Flashcards