Question 1

Which of the following statements best describes the difference between an SN1 and an SN2 reaction mechanism?

Accepted Answer

SN2 reactions are bimolecular and proceed via a single concerted step, while SN1 reactions are unimolecular and proceed via a carbocation intermediate.

Question 2

Which of the following alkanes has the lowest energy conformation when viewed in a Newman projection down the C2–C3 bond?

Accepted Answer

The anti conformation of butane.

Question 3

A forensic chemist finds a sample containing a compound with the molecular formula $$C_4H_{10}. $$Which of the following is a correct IUPAC name for a possible structure?

Accepted Answer

2-methylpropane

Question 4

Which of the following statements about chiral molecules is correct?

Accepted Answer

A molecule that is not superimposable on its mirror image is chiral.

Question 5

Which of the following best describes the difference between enantiomers and diastereomers?

Accepted Answer

Enantiomers have identical physical properties except for their interaction with plane-polarized light, while diastereomers have different physical properties.

Question 6

Which of the following is the correct Fischer projection for D-glucose?

Accepted Answer

A Fischer projection with the hydroxyl group on C-5 on the right and the aldehyde group at the top.

Question 7

A sample contains a mixture of $$eta-D-$$glucose and $$eta-D-$$galactose. Which term best describes their relationship?

Accepted Answer

Epimers

Question 8

Which of the following statements about the base pairing in DNA is correct?

Accepted Answer

Adenine pairs with thymine via two hydrogen bonds.

Question 9

Which of the following amino acids has a side chain that is positively charged at physiological pH?

Accepted Answer

Lysine

Question 10

A forensic scientist is analyzing a sample suspected to contain amphetamine. Which functional group is present in amphetamine?

Accepted Answer

A primary amine group

Question 11

Which of the following best describes the primary structure of a protein?

Accepted Answer

The sequence of amino acids linked by peptide bonds

Question 12

Which of the following conditions favors an E2 elimination reaction over an SN2 substitution?

Accepted Answer

A tertiary alkyl halide with a strong base

Question 13

Which of the following is the correct general structure of an amino acid?

Accepted Answer

$$\mathrm{H_2N{-}CHR{-}COOH}$$

Question 14

Which of the following statements about mutarotation is correct?

Accepted Answer

Mutarotation is the change in optical rotation due to the equilibrium between alpha and beta anomers of a sugar in solution.

Question 15

Which of the following best describes the Cahn-Ingold-Prelog priority rules for assigning R/S configuration?

Accepted Answer

Assign priorities based on atomic number; the group with the lowest priority should be oriented away from the observer.

Question 16

Which of the following is a correct statement about the iso-electric point ($$pI) of an $$amino acid?

Accepted Answer

The $$pI is $$the pH at which the amino acid has no net electric charge.

Question 17

Which of the following best explains why tertiary alkyl halides do not undergo SN2 reactions efficiently?

Accepted Answer

Steric hindrance prevents the nucleophile from attacking the carbon center in tertiary alkyl halides.

Question 18

Which of the following is a correct IUPAC name for the compound with the structure $$\mathrm{CH_3CH_2CH_2Br}$$?

Accepted Answer

1-bromopropane

Question 19

Which of the following statements about peptide bond formation is correct?

Accepted Answer

A peptide bond forms between the carboxyl group of one amino acid and the amino group of another, releasing water.

Question 20

Which of the following best describes an anomer in carbohydrate chemistry?

Accepted Answer

Isomers that differ at the new chiral center formed on ring closure (the anomeric carbon).

Organic Chemistry Fundamentals for Forensic Laboratory Research: Course Syllabus and Study Guide

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