Q: Which of the following is the correct order of increasing acidity (lowest to highest) for the following compounds: ethanol, acetic acid, phenol?

$$\text{ethanol} \u003c \text{phenol} \u003c \text{acetic acid}$$

Question 1

Which of the following statements best describes the geometry and bond rotation of a carbon atom with sp$$^2$$ hybridization in ethene ($$C_2H_4$$)?

Accepted Answer

The carbon is trigonal planar and rotation about the double bond is restricted.

Question 2

Which of the following molecules contains a chiral center?

Accepted Answer

2-chlorobutane ($$CH_3CHClCH_2CH_3)$$

Question 3

Given the following pKa values, which compound is the strongest acid?

Accepted Answer

Hydrochloric acid ($$pK_a = -7)$$

Question 4

Which of the following best explains why the C–H bond in ethyne ($$C_2H_2) is $$more acidic than the C–H bond in ethane ($$C_2H_6$$)?

Accepted Answer

The sp hybridized carbon in ethyne is more electronegative, stabilizing the negative charge on the conjugate base.

Question 5

Which of the following is the correct IUPAC name for the compound with the structure $$CH_3CH_2CH_2OCH_3$$?

Accepted Answer

1-methoxypropane

Question 6

Which of the following statements about chair conformers of cyclohexane is TRUE?

Accepted Answer

A ring flip interconverts axial and equatorial positions.

Question 7

Which of the following best describes the difference between conformational and configurational isomers?

Accepted Answer

Conformational isomers can be interconverted by rotation about single bonds, while configurational isomers require bond breaking to interconvert.

Question 8

Which of the following compounds is a meso compound?

Accepted Answer

2,3-dibromobutane (with both Br on the same side)

Question 9

Which of the following best describes the effect of hydrogen bonding on the boiling point of alcohols compared to alkanes of similar molecular weight?

Accepted Answer

Alcohols have higher boiling points due to strong hydrogen bonding.

Question 10

Which of the following is the correct order of increasing acidity (lowest to highest) for the following compounds: ethanol, acetic acid, phenol?

Accepted Answer

$$	ext{ethanol} \u003c 	ext{phenol} \u003c 	ext{acetic acid}$$

Question 11

A molecule has the following structure: $$CH_3CH_2CH(OH)CH_3$. What is the correct IUPAC name?

Accepted Answer

2-butanol

Question 12

Which of the following best describes the relationship between (R)-2-butanol and (S)-2-butanol?

Accepted Answer

They are enantiomers.

Question 13

Which of the following is the correct Newman projection for the lowest energy conformation of ethane ($$C_2H_6$$)?

Accepted Answer

Staggered conformation with a dihedral angle of $$60^\circ$$

Question 14

Which of the following statements about resonance is TRUE?

Accepted Answer

Resonance delocalizes electrons, stabilizing the molecule.

Question 15

Which of the following curved arrow notations correctly represents the movement of electrons in the deprotonation of acetic acid by hydroxide ion?

Accepted Answer

Arrow from lone pair on $$OH^- to $$the hydrogen of acetic acid, and arrow from O–H bond to the oxygen atom of acetic acid.

Question 16

Which of the following best explains why fluorine substituents increase the acidity of acetic acid?

Accepted Answer

Fluorine is highly electronegative and withdraws electron density through induction, stabilizing the conjugate base.

Question 17

Which of the following is the correct IUPAC name for the compound with the structure $$CH_3CH_2NH_2$$?

Accepted Answer

Ethylamine

Question 18

Which of the following best describes the difference between E and Z alkenes?

Accepted Answer

E alkenes have the highest priority groups on opposite sides of the double bond; Z alkenes have them on the same side.

Question 19

Which of the following statements about the solubility of ethers in water is TRUE?

Accepted Answer

Ethers can form hydrogen bonds with water, increasing their solubility compared to alkanes.

Question 20

Which of the following best describes the relationship between cis-1,2-dimethylcyclohexane and trans-1,2-dimethylcyclohexane?

Accepted Answer

They are diastereomers.

Organic Chemistry Study Guide: Chapters 1–4 Core Concepts

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