Texas A&M University (TAMU) CHEM 222 Elements of Organic and Biological Chemistry Exam 1 Practice

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• What is the product of Jones oxidation of a secondary alcohol?
• Why is acetic acid stronger than ethanol?
• Which statement best describes anthocyanins?
• Which hybridization corresponds to three electron groups with zero lone pairs?
• What term describes the arrangement of bonds around a central atom, ignoring lone pairs?
• In cyanohydrin formation, what intermediate forms immediately after nucleophilic attack of cyanide on the carbonyl carbon?
• Which pi-electron count could be aromatic according to Huckel's rule (for some integer n)?
• In halogenation of alkenes, what intermediate forms and what is the resulting stereochemistry?
• What term describes the arrangement around a double bond known as E/Z isomerism?
• What IR features indicate carbonyls and O-H groups?
• Which type of intermolecular force is the attraction between an ion and a polar bond?
• In SN2 reactions, which substrate is most reactive toward nucleophilic attack?
• Ionic bonds are best described as what process between atoms?
• Dehydration of the aldol product from acetaldehyde yields which enone?
• Amphoteric substances are defined as substances that can act as acids in some reactions and as bases in others.
• Compared to ketones, aldehydes are generally more reactive toward nucleophiles because of which factors?
• Which sequence of reagents achieves anti-Markovnikov hydration of alkenes?
• Provide approximate pKa values for carboxylic acids, alcohols, and alkanes.
• Acetal formation from carbonyls typically requires acid catalysis and a diol; which condition drives the equilibrium toward acetal formation?
• Which expression correctly represents the Henderson–Hasselbalch equation for a buffer?
• Rank carbocation stability and name common rearrangements that occur in SN1 reactions.
• What is the general structure of a Grignard reagent?
• Which statement correctly describes base-catalyzed hydrolysis (saponification) of an ester?
• What pattern in mass spectrometry indicates the presence of chlorine in a compound?
• In 13C NMR, carbonyl carbons resonate in which range?
• Which functional group typically shows a broad peak around 3300 cm-1 in IR spectroscopy?
• Which intermolecular force exists between all atoms and is described as the weakest?
• What is the IUPAC name for CH3CH2OH?
• In hydroboration-oxidation, why does the hydroxyl group end up on the less substituted carbon?
• In electrophilic aromatic substitution, which step is rate-determining?
• Which of the following describes the behavior of weak acids and bases in water?
• A glycosidic bond in disaccharides is formed by linking the anomeric carbon of one sugar to a hydroxyl group of another sugar, forming an acetal linkage during dehydration.
• Which equation represents Henderson–Hasselbalch?
• A negative ΔH indicates heat flow in which direction?
• What is keto-enol tautomerism, and what is a common example mentioned?
• SNAr on an aryl halide proceeds via a Meisenheimer complex and requires electron-withdrawing groups and a good leaving group; often fluoride as leaving group.
• Among ethanol and acetic acid, which is the stronger acid?
• Which hybridization corresponds to two electron groups around the central atom?
• Which interaction is classically observed when an ionic species interacts with a polar molecule?
• Which product is typically obtained when PCC oxidizes a primary alcohol?
• Bronsted-Lowry acid is
• In ozonolysis, the carbon–carbon double bond is cleaved to form what kinds of fragments?
• Which statement about solvent effects on SN1 versus SN2 reactions is true?
• Which statement correctly defines the equilibrium constant for a chemical reaction that forms products from reactants?
• Three electron groups, two lone pairs, one bond (AX1E2) produce which molecular geometry?
• Dipole–dipole interactions are described as what?
• Which force is described as second strongest after hydrogen bonds and commonly referred to as the attraction between an ion and a polar bond?
• Differentiate Markovnikov and anti-Markovnikov hydration of alkenes and the reagents that provide each product.
• According to Le Chatelier's principle, what happens when more reactant is added to a system at equilibrium?
• According to Huckel's rule, how many pi electrons do cyclopentadienyl anion and cyclopentadienyl cation have, and what is their aromaticity status?
• What is the product of catalytic hydrogenation of an alkyne with H2 and a metal catalyst, as described in the source?
• Which description best characterizes a Grignard reagent?
• What stereochemical outcome is typical for SN2 reaction at a chiral center?
• NaBH4 is commonly used to reduce which functional groups to alcohols?
• In SN1 reactions, the planar carbocation intermediate causes what stereochemical outcome at a chiral center?
• Keto-enol tautomerism involves interconversion between which two forms?
• If a proton is split by two equivalent neighboring protons, what is the expected multiplicity?
• Which statement correctly describes London Forces?
• If the equilibrium constant K equals 1, what does this imply about the relative amounts of reactants and products?
• Three electron groups, one lone pair (AX2E1) produce which molecular geometry?
• In a chemical equilibrium, which statement is true?
• In 1H NMR, which region is commonly associated with aliphatic protons?
• Why does the addition of HBr to an alkene in the presence of peroxides yield an anti-Markovnikov product?
• Describe the general mechanism of nucleophilic acyl substitution for an acid chloride reacting with water.
• If the equilibrium constant K is greater than 1, which statement best describes the composition at equilibrium?
• What does the Tollens test indicate in organic analysis?
• Nonpolar covalent bonds involve what range of electronegativity difference?
• For a species with two electron groups around the central atom, the electron geometry is Linear. What is the bond angle?
• Why is amide nitrogen far less basic than amine nitrogen?
• A bond between two nonmetals with a relatively large electronegativity difference is typically what type of bond?
• What is the overall order of a reaction with rate law rate = k[A][B]?
• In 1H NMR, a tert-butyl group typically appears as a singlet around which range integrating to how many hydrogens?
• Maltose has an alpha-1,4-glycosidic linkage between two glucose units.
• Which force involves attractions between -OH or -NH groups and contributes to cohesion in molecules like alcohols?
• Given pKa = 4.8 and [A−]/[HA] = 9, approximate pH.
• If a solution contains more acid than base, which statement about pH and pKa is true?
• What is the product after CH3MgBr adds to formaldehyde followed by aqueous workup?
• What is a common protecting group transformation for carbonyls in organic synthesis?
• Provide typical 13C NMR ranges for alkane carbons, alkenes, carbonyls, and aromatics.
• Which two major reactions involve enolates as nucleophiles in carbonyl chemistry?
• When two bromine atoms are added across an alkene, where do they end up?
• Which statement lists the correct maximum number of bonds for H, C, N, O, and F/Cl/Br/I?
• If the equilibrium constant K for a reaction is less than 1, which statement best describes the composition of the mixture at equilibrium?
• Which statement describes the typical preparation of a Grignard reagent in the laboratory?
• Which base would tend to favor E2 elimination over SN2 for a secondary alkyl halide?
• What term describes the arrangement of all electron groups around an atom, including lone pairs and bond electrons?
• Predict the major product of hydration of an internal alkyne and explain regioselectivity.
• Catalytic hydrogenation of an alkyne (R-C≡CH) with H2 and a metal catalyst produces which product?
• Which statement best defines chirality, and what is a common example?
• Which statement best describes symmetry around a central atom in a molecule?
• In E/Z isomerism, what does the Z designation signify about the higher-priority substituents?
• What is the purpose of a protecting group in organic synthesis?
• What is the stereochemical outcome of halogenation across a double bond?
• If a solution contains more base than acid, which statement about pH and pKa is true?
• In 1H NMR, which signal is most diagnostic of an aldehyde proton?
• What is the molecular geometry of AX2E2?
• In an aldol condensation, what type of bond is formed between two molecules?
• Covalent bonds can be single, double, or triple depending on the number of shared electron pairs.
• Which statement best describes nucleophilicity versus basicity?
• Which functional group is present in CH3COOH?
• What is true about sigma bonds?
• In hydroboration-oxidation of propene, the hydroxyl group ends up on which carbon of the original alkene?
• Amphoteric compounds can act as
• Retro-aldol reaction is the reverse of aldol condensation; under what conditions does it occur?
• Which description correctly characterizes a nonpolar covalent bond?
• If a molecule has two stereocenters and no symmetry, what is the maximum number of stereoisomers?
• An electronegativity difference around 1.75 for a bond between a metal and a nonmetal would be classified as what type of bond?
• What is the product of adding Br2 to an alkene?
• Bronsted-Lowry base is
• Grignard reagents are typically prepared in which solvent environment?
• Which intermolecular force involves -OH or -NH groups and contributes to intermolecular attraction?
• Which statement about carbocation stability is true?
• According to Le Chatelier's principle, if more product is added to a system at equilibrium, which direction will the reaction shift?
• Which hybridization corresponds to four electron groups with zero lone pairs?
• Which statement correctly ranks Salt bridges and Dipole-Dipole interactions by strength?
• What is the stereochemical outcome of catalytic hydrogenation of alkenes with H2 and Pd/C?
• If [OH-] is 1 x 10^-5 M, what is [H+] and the pH of the solution?
• Which rule is used to assign absolute configuration (R or S) at a stereocenter?
• Which statement about diastereomers is true?
• How do you assign R/S configuration at a chiral center?
• Which force arises from temporary fluctuations in electron distribution and is typically the weakest among common intermolecular forces?
• Why is the peptide bond planar?
• Conjugates are compounds that differ in
• Which nitrogen is more basic?
• If [OH-] is 2.0 x 10^-3 M, what is [H+]?
• Electronegativity is defined as what property?
• Pi bonds are formed by which type of overlap?
• Covalent compounds are defined by which process?
• Which statement correctly identifies an acidic solution?
• Three electron groups, zero lone pairs (AX3) have which molecular geometry?
• When a salt dissolves in water, the dominant intermolecular interaction is typically ...
• Which of the following best describes ortho/para-directors and meta-directors in electrophilic aromatic substitution?
• Polar covalent bonds involve what range of electronegativity difference?
• What is the major product of hydroboration-oxidation of propene?
• In 1H NMR, a singlet at about 2.1 ppm integrating to 3H typically indicates which group?
• Which statement correctly distinguishes E1 from E2 mechanisms?
• Which intermediate forms after Grignard reagent adds to formaldehyde before protonation?
• Which feature of an alkene largely determines whether ozonolysis yields aldehydes vs ketones?
• Equilibrium occurs when
• In enolate alkylation, the electrophile attacks at which position on the enolate?
• In glucose, alpha and beta anomers differ at which carbon?
• Why must the beta-hydrogen be anti-periplanar in an E2 reaction, and what occurs if not?
• At physiological pH, the zwitterionic form of amino acids has which net charge?
• In a cyclic sugar, what does the anomeric carbon refer to?
• Which best describes the carbon atom in methane (CH4) in terms of hybridization and geometry?
• Which intermediate is formed immediately after electrophile attack in electrophilic aromatic substitution?
• Which intermolecular force is the attraction between an ion and a polar bond, and is described as second strongest?
• What bond links amino acids in a protein and what is a key feature of that bond?
• In 13C NMR, where would you typically see a carbonyl carbon compared to an sp3 carbon?
• Which statement correctly describes SN1 and SN2 mechanisms?
• How do Tollens' test and Fehling's test differ, and what functional group do they detect?
• Define enolate and describe how it is formed.
• Which statement best defines a Grignard reagent?
• In aldose ring formation, which carbon becomes the anomeric carbon during ring closure?
• In 13C NMR, aromatic carbons typically resonate in which range?
• What does the R/S notation indicate for a stereocenter?
• Enantiomers are non-superimposable mirror images; diastereomers are not mirror images; a meso compound is achiral due to an internal plane of symmetry.
• In SN2 reactions, how does changing nucleophile concentration affect the reaction rate?
• Which reagent is commonly used to convert a primary alcohol to the corresponding alkyl bromide via SN2?
• Which intermolecular force is described as the attraction between -OH or -NH groups and is considered the second strongest?
• How do Cl and Br isotopic patterns appear in mass spectra?
• How many stereoisomers are possible for a molecule with two stereocenters and no symmetry?
• Which statement best contrasts SN1 and SN2 mechanisms?
• Which statement about pH scales is correct?
• A triple bond consists of
• Define conjugation and explain how it stabilizes molecules.
• State Markovnikov's rule for addition of HX to an asymmetric alkene.
• Describe hydroboration-oxidation: regioselectivity and stereochemistry when reacting with 1-hexene.
• Which compound is produced when a primary alcohol is oxidized with PCC (pyridinium chlorochromate)?
• Which statement correctly identifies pi bonds?
• In Fischer esterification, what effect does removing water have on the reaction?
• When equal amounts of acid and base are present, the pH equals the pKa.
• Salt bridge: Which description is correct?
• If [A-] = [HA], what is the pH relative to pKa?
• In Fischer esterification, what are the typical reagents and products?
• Which force is described as second strongest after hydrogen bonds and occurs between ions and polar molecules?
• Which spectroscopy is typically used to identify functional groups such as O–H and C=O?
• Amphoteric substances are defined as substances that can act as acids in some reactions and as bases in others.
• How does halogenation of alkenes occur and what is the stereochemical outcome?
• Which statement correctly describes how strong acids and bases behave in water?
• How are E and Z configurations assigned for alkenes using CIP priorities?
• In 1H NMR, what does a doublet indicate?
• In an SN1 reaction, which carbocation is typically formed first?
• Which metal catalyst is given as an example for hydrogenation in the material?
• A carbon–carbon double bond consists of
• What is pH defined as?
• What is the effect of a catalyst on a reaction at equilibrium?
• Which statement best describes a buffer?
• In cyclohexane chairs, which orientation is usually preferred for bulky substituents and why?
• Ionic compounds are best described as what kind of bonds and elements?
• Four electron groups, zero lone pairs (AX4) produce which molecular geometry?
• In ozonolysis of an alkene, what are the general carbonyl-containing products?
• According to the octet rule, atoms gain, lose, or share electrons to achieve what electron configuration?
• Which statement best describes the oxidation behavior distinguishing aldehydes from ketones under mild oxidants?
• Reaction of a Grignard reagent with formaldehyde followed by workup yields which product?
• Explain oxymercuration-demercuration mechanism and why it avoids rearrangements.
• Which of the following best describes a Grignard reagent?
• Markovnikov addition of HBr to propene yields which major product?
• Four electron groups, one lone pair (AX3E1) produce which molecular geometry?
• Which base is commonly used to form enolates (enolate formation)?
• Why are nitro groups meta-directors in electrophilic aromatic substitution?
• Which rearrangements occur in SN1 reactions?
• Predict the major product of terminal alkyne hydration with HgSO4/H2SO4.
• Which statement correctly describes the difference between E and Z isomers?
• Provide typical 1H NMR chemical shift ranges for alkane, alkene, aldehyde, and carboxylic acid protons.
• Which statement about catalysts is true?
• Which option correctly describes sigma bonds in relation to pi bonds?
• Which force is weaker than both hydrogen bonds and ion-dipole interactions in the simplified ranking?
• Which category of intermolecular forces is present in nonpolar molecules and is typically the weakest among common interactions?
• What feature does the peptide bond exhibit due to partial double-bond character?
• A buffer is most effective within how many pH units of its pKa?
• Which statement about SN1 reactions is correct?
• Hydrogenation of an alkene in the presence of a metal catalyst such as platinum yields which product?
• What is the major product of acid-catalyzed hydration of ethene (H2C=CH2)?
• Which statement about anthocyanins is true?
• Describe the aldol condensation of acetaldehyde with itself and the major product after dehydration.
• Compared to a single bond, what is true about a multiple bond?
• Which description correctly states the hybridization and geometry of the carbon atoms in ethene (C2H4)?
• How can you convert an alcohol into a good leaving group for substitution reactions?
• Which statement contrasts strong acids/bases with weak acids/bases in water?
• If [H+] equals [OH-], what is the pH and the nature of the solution?
• Ionic compounds are typically formed between which types of elements?
• What is the molecular geometry of methane, CH4?
• Which statement correctly identifies a neutral solution?
• What are typical pKa values for the carboxyl and amino groups of amino acids?
• Which statement correctly describes the hybridization and geometry of carbon atoms in ethene?
• Mutarotation is the interconversion between alpha and beta anomers in solution via open-chain form.
• Four electron groups, three lone pairs (AX1E3) produce which molecular geometry?
• Which intermolecular force is typically weaker than hydrogen bonds and ion-dipole interactions, yet is present across all atoms?
• For a primary alcohol to convert to an alkyl bromide via SN2, which type of alcohol is most suitable?
• Why are enolates good nucleophiles in carbonyl chemistry?
• Consider ester hydrolysis. Which statements correctly describe the products under acidic hydrolysis and under basic (saponification) conditions?
• The anomeric carbon is the carbon derived from the carbonyl carbon during ring closure.
• Why are carboxylate anions more stable than alkoxide anions?
• Which statement describes the relationship between base strength and the pKa of the conjugate acid?
• Four electron groups, two lone pairs (AX2E2) produce which molecular geometry?
• In a base-catalyzed aldol condensation of acetaldehyde, what is the typical initial product?
• For amino acids with only non-ionizable side chains, pI is approximately equal to which expression?
• During cyanohydrin formation with an aldehyde and HCN, the final product contains which two functional groups?