Question 1

Which of the following statements best explains why conjugated dienes absorb at longer wavelengths in UV/Vis spectroscopy compared to isolated dienes?

Accepted Answer

Conjugated dienes have delocalized electrons, which lowers the energy gap between the HOMO and LUMO.

Question 2

A student is given a compound with the molecular formula $$C_7H_8O$$ and is told it is a phenol derivative. Which qualitative test would best confirm the presence of the phenol functional group?

Accepted Answer

Bromine water test, which gives a white precipitate with phenols.

Question 3

Which of the following is the correct IUPAC name for the compound shown below?

$$\mathrm{CH_3CH_2CH_2COOCH_3}$$

Accepted Answer

Methyl butanoate

Question 4

Which of the following compounds would have the highest boiling point?

A. $$\mathrm{CH_3CH_2OH}

B$$. $$\mathrm{CH_3OCH_3}

C$$. $$\mathrm{CH_3CH_2CH_3}

D$$. $$\mathrm{CH_3COOH}$$

Accepted Answer

D. $$\mathrm{CH_3COOH}$$

Question 5

Which of the following best describes the mechanism of nucleophilic acyl substitution in carboxylic acid derivatives?

Accepted Answer

A nucleophile attacks the carbonyl carbon, forming a tetrahedral intermediate, which then eliminates a leaving group.

Question 6

Which of the following statements about electrophilic aromatic substitution (EAS) is correct?

Accepted Answer

Electron-donating groups on benzene activate the ring and direct new substituents to the ortho and para positions.

Question 7

A chemist wants to synthesize 2-butanone from 1-butanol. Which sequence of reagents would accomplish this transformation?

Accepted Answer

1. $$\mathrm{$$PBr_3$$}$$; 2. $$\mathrm{Mg}$$, ether; 3. $$\mathrm{CO_2$}$$; 4. $$\mathrm{H_3O^+}$$; 5. $$\mathrm{CH_3MgBr}$$; 6. $$\mathrm{H_3O^+}$$; 7. $$\mathrm{PCC}$$

Question 8

Which of the following best explains why epoxides are more reactive toward nucleophilic attack than ethers?

Accepted Answer

Epoxides have significant ring strain due to their three-membered ring structure.

Question 9

Which of the following is the correct product of the reaction between benzene and acetyl chloride ($$\mathrm{CH_3COCl}) in $$the presence of $$\mathrm{$$AlCl_3$$}$$?

Accepted Answer

Acetophenone ($$\mathrm{C_6H_5COCH_3})$$

Question 10

Which of the following statements about the structure of nucleic acids is correct?

Accepted Answer

The backbone of nucleic acids consists of alternating sugar and phosphate groups linked by phosphodiester bonds.

Question 11

Which of the following reactions is an example of a carbonyl condensation reaction?

Accepted Answer

Aldol condensation: $$\mathrm{2~CH_3CHO \rightarrow CH_3CH(OH)CH_2CHO}$$

Question 12

Which of the following best describes the difference between an aldose and a ketose carbohydrate?

Accepted Answer

An aldose contains an aldehyde group, while a ketose contains a ketone group.

Question 13

Which of the following statements about synthetic polymers is correct?

Accepted Answer

Polyethylene is formed by the addition polymerization of ethylene monomers.

Question 14

Which of the following amino acids is most likely to be found at the active site of an enzyme due to its nucleophilic side chain?

Accepted Answer

Serine

Question 15

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

Accepted Answer

The carboxylate ion is stabilized by resonance, delocalizing the negative charge over two oxygen atoms.

Question 16

A student is asked to rank the following compounds in order of increasing polarity:

1. $$\mathrm{CH_3CH_2CH_3}
2$$. $$\mathrm{CH_3CH_2OH}
3$$. $$\mathrm{CH_3COOH}$$

Which is the correct order?

Accepted Answer

$$\mathrm{CH_3CH_2CH_3} \u003c \mathrm{CH_3CH_2OH} \u003c \mathrm{CH_3COOH}$$

Question 17

Which of the following is the correct structure for the product of the nucleophilic addition of $$\mathrm{$$NaBH_4$$} to $$acetone ($$\mathrm{CH_3COCH_3}$$)?

Accepted Answer

$$\mathrm{CH_3CH(OH)CH_3$}$$

Question 18

Which of the following best describes the role of molecular modeling in organic chemistry?

Accepted Answer

It allows visualization of three-dimensional structures and prediction of physical and chemical properties.

Question 19

Which of the following is a correct statement about the hydrolysis of an amide under acidic conditions?

Accepted Answer

It produces a carboxylic acid and an ammonium ion.

Question 20

Which of the following best explains why thiols are more acidic than alcohols?

Accepted Answer

Sulfur is larger and less electronegative than oxygen, stabilizing the negative charge on the thiolate ion.

CHE 302 – General Organic Chemistry II: Syllabus and Course Structure

Guida di studio - Domande di pratica

Study guide - Flashcard