Organic Chemistry ACS Sample Questions - Selected Questions

Sep 21, 2026

Uploaded by Rowan

ACS examination guide covering selected organic chemistry questions across core topics. It includes practice items on nomenclature (IUPAC naming), structure interpretation with Lewis structures, hybridization and resonance, aromaticity, and related stability reasoning. Additional coverage spans acid-base predominance near pH 7, resonance structure identification, stereoisomerism including R configuration and Newman projections, diastereomer stability, and mechanisms such as nucleophilic substitution/elimination and dehydration. Electrophilic and nucleophilic additions and carbonyl hydrolysis questions are also included, with answer keys for multiple items.

LanguageEnglish

CategoryExam

FormatPDF

Pages20

Reading Time50 min

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Nomenclature

Structure, Hybridization, Resonance, Aromaticity

Acid and Bases

Stereoisomerism

Nucleophilic Substitution and Elimination

Electrophilic Additions

Nucleophilic Addition at Carbonyl Groups

Nucleophilic Substitution at Carbonyl Groups

ACS Examination guide (Selected Questions) Organic Chemistry Nomenclature 1. What is the IUPAC names for this compound? a) 1-tert-butyl-2-butanol b) 5,5-dimethyl-3-hexanol c) 2,2-dimethyl-4-hexanol d) 1,1,1-trimethy-3-pentanol 4.What is the IUPAC name for this structure? a) 3-bromo-4-methylheptanone b) 5-bromo-4-methylheptanone c) 5-bromo-4-methyl-3-heptanone d) 3-bromo-4-methyl-5-heptanone 9. What is the IUPAC name of this compound? a) m-hydroxy-m-xylene b) 3,5-dimethylphenol c) 2,4-dimethyl-6-hydroxybenzene d) 3-hydroxy-5-methyltoluene Answer: 1, b; 4, c; 9, b. Structure, Hybridization, Resonance, Aromaticity Chapter Book p 17,18,19 1) identify the lowest-energy Lewis structure for nitrogen oxide. (Formal charges not shown.) 8) The heat of combustion (per CH2) of several cycloalkanes is listed below. Based on the data given, which of these cycloalkanes would be considered most stable. a) cyclobutane b) cyclopentane c) cyclooctane d) cyclopentadecane 11) Which pair consists of the resonance structure? Answer: 1, c; 8, d;11, a Acid and Bases Book P 30, 31 1. Which structure corresponds to the predominant form of this molecule near pH 7? 4. Which is the order from the strongest acid to the weakest acid for these species? A) II > IV > I > III B) III > I > IV > II C) III > IV > I > II D) II > I > IV > III 8) Which of the indicated protons in this compound would have the smallest pKa values? Stereoisomerism Book P38, 39, 1) Which molecule has the R configuration? 6) Which Newman projection represents the most stable configuration of (CH3)2CHCH(CH3)2 Answer: 1 , c ;4, a;8, d . 10) Which diastereoisomer is most stable? Answer: 1, c; 6, c, 10, b. Nucleophilic Substitution and Elimination 2) When 2-bromo-2-methybutane is treated with a base, a mixture of 2-methyl-2-butene and 2-methyl-1-butene is produced When potassium hydroxide is the base, 2 methyl-1-butene accounts for 45% of the mixture, but when potassium tert-butoxide is the base, 2 methyl-1-butene accounts for 70% of the mixture. What would you predict for the percent of 2 methyl-1-butene in the mixture if the potassium prop-oxide were the base? (a) Less than 45% (b) 45% (c) between 45% and 70% (d) more than 70% 11) Why would the concentrated hydrobromic acid be an inappropriate catalyst for the dehydration of alcohols? a) HBr is too weakly acidic to protonate the alcohol. b) The conjugate base, Br- , is a good nucleophile and it would attack the carbocation to form an alkyl bromide. c) HBr is strongly acidic, so the water molecule would not be a good leaving group after protonation of the alcohol. d) HBr would be more likely to promote rearrangement of the carbocation intermediate. 17) What would be the first step in the dehydration of cyclohexanol in sulfuric acid? a) loss of OH b) loss of H+ by the alcohol c) formation of a sulfite ester d) protonation of the alcohol Answer: 2, c, 11, b, 17, d. Electrophilic Additions 7) which set of the reagents will carry out the conversion shown? Answer: 7, c Nucleophilic Addition at Carbonyl Groups 8) which compound would be most rapidly hydrolyzed by aqueous HC to give methanol as one of the products? 12) which is the best reagent for this conversion? 17) which reagent will accomplish the conversion shown? Answer: 8, d, 12, b, 17, d. Nucleophilic Substitution at Carbonyl Groups 1) This reaction that is typical of carboxylic acids, ester, acid halides, anhydrides, and amides is called. (a) nucleophilic non-acyl substitution (b) nucleophilic addition (c) nucleophilic acyl substitution (d) electrophilic substitution 3) Which would be hydrolyzed most slowly with aqueous NaOH?

FAQs

What types of organic chemistry questions are included in this ACS selected question guide?

It includes questions on IUPAC nomenclature, Lewis structure interpretation, hybridization/resonance/aromaticity, acid-base predominance, stereoisomerism, and reaction mechanisms such as substitution, elimination, and dehydration.

How are acid-base questions handled around pH 7 in the guide?

The guide asks which molecular structure is predominant near pH 7 and also asks for the order of acids from strongest to weakest among given species.

What mechanism-related topics appear in the nucleophilic substitution and elimination section?

It includes base-dependent product distributions for alkene formation, questions about inappropriate catalysts for alcohol dehydration, and a prompt asking the first step in dehydration of cyclohexanol in sulfuric acid.

Sep 21, 2026

Uploaded by Rowan

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