TAMU CHEM 238 Final Exam Questions with Verified Answers Latest Version 2025 Graded A+
1. Reaction of ethyl magnesium bromide with water will generate?
a. ethanol
b. ethane
c. butane
d. ethyl magnesium hydroxide
e. a peroxide - Answers b
2. Under conditions of thermodynamic control, product distribution is governed by:
a. the relative stabilities of the products
b. the relative energies of the transition states leading to the products
c. the rate at which each product is formed
d. a and b
e. b and c - Answers a
3. Which of the following statements is false for the reduction of camphor?
a. A hydride is transferred from the borohydride ion to the carbonyl of camphor.
b. Isoborneol is the major product.
c. One mole of NaBH4 can reduce four moles of camphor.
d. The borohydride ion can approach the camphor more easily from the exo side.
e. If LiAlH4 is used instead of NaBH4, ethanol cannot be used as a solvent. - Answers d
4. In an aqueous organic extraction,
a. the less dense layer is on top
,b. the more dense layer is on top
c. aqueous layer is always on top
d. the phase with less sample dissolved is always on top
e. the organic layer is always on top - Answers d
5. The dimeric structure of diphosphomevalonate decarboxylase involves:
a. Covalent amide linkages
b. Van der Waals interactions of non-polar side chains
c. Interactions of polar sidechains of amino acids
d. Hydrogen bonding of amide carbonyls with nearby amide N-H bonds
e. Covalent disulfide linkages - Answers c
6. A good classification test (reaction which provides easy detection of positive result) for a carboxylic
acid is
a. the Hinsberg test
b. treatment with 2,4-dinitrophenylhydrazine solution
c. sodium fusion
d. the evolution of carbon dioxide upon addition of sodium bicarbonate
e. reaction with thionyl chloride - Answers d
7. What will happen if you don't cool the diazonium chloride salt before addition of phenol?
a. It will still produce same diazonium compound
b. It will be converted to a phenol
c. It will be converted to an amine
d. It will produce a different diazonium compound
e. It will react with unreacted amine present in solution - Answers b
, 8. Which statement best describes the first steps in the aldol condensation?
a. a-hydrogen abstraction followed by enolate formation
b. nucleophilic attack by hydroxide on carbonyl carbon followed by hydride transfer
c. aldehyde hydrogen abstraction followed by enolate formation
d. aldehyde hydrogen abstraction followed by hydride transfer
e. a-hydrogen abstraction leading to enolate formation - Answers e
9. Which combination might give an ester that will not be volatile enough to have significant odor?
a. benzyl alcohol and salicylic acid
b. methyl alcohol and formic acid
c. methyl alcohol and acetic acid
d. acetic acid and 2-methyl-1-propanol
e. formic acid and ethyl alcohol - Answers a
10. Which compound will give a positive iodoform test? - Answers CH3C=O group or the CH3CH(OH
aldehyde or ketone
11. The purpose of spotting a mixture of all possible products on the TLC plate is to:
a. identify which product was synthesized by comparing your product to the Rf values from
the mixture
b. demonstrate which products you should have had
c. identify the dinitration product
d. identify any impurities
e. for comparison of the crude product - Answers a
12. Which of the following chemicals will not react with Grignard Reagent?
1. Reaction of ethyl magnesium bromide with water will generate?
a. ethanol
b. ethane
c. butane
d. ethyl magnesium hydroxide
e. a peroxide - Answers b
2. Under conditions of thermodynamic control, product distribution is governed by:
a. the relative stabilities of the products
b. the relative energies of the transition states leading to the products
c. the rate at which each product is formed
d. a and b
e. b and c - Answers a
3. Which of the following statements is false for the reduction of camphor?
a. A hydride is transferred from the borohydride ion to the carbonyl of camphor.
b. Isoborneol is the major product.
c. One mole of NaBH4 can reduce four moles of camphor.
d. The borohydride ion can approach the camphor more easily from the exo side.
e. If LiAlH4 is used instead of NaBH4, ethanol cannot be used as a solvent. - Answers d
4. In an aqueous organic extraction,
a. the less dense layer is on top
,b. the more dense layer is on top
c. aqueous layer is always on top
d. the phase with less sample dissolved is always on top
e. the organic layer is always on top - Answers d
5. The dimeric structure of diphosphomevalonate decarboxylase involves:
a. Covalent amide linkages
b. Van der Waals interactions of non-polar side chains
c. Interactions of polar sidechains of amino acids
d. Hydrogen bonding of amide carbonyls with nearby amide N-H bonds
e. Covalent disulfide linkages - Answers c
6. A good classification test (reaction which provides easy detection of positive result) for a carboxylic
acid is
a. the Hinsberg test
b. treatment with 2,4-dinitrophenylhydrazine solution
c. sodium fusion
d. the evolution of carbon dioxide upon addition of sodium bicarbonate
e. reaction with thionyl chloride - Answers d
7. What will happen if you don't cool the diazonium chloride salt before addition of phenol?
a. It will still produce same diazonium compound
b. It will be converted to a phenol
c. It will be converted to an amine
d. It will produce a different diazonium compound
e. It will react with unreacted amine present in solution - Answers b
, 8. Which statement best describes the first steps in the aldol condensation?
a. a-hydrogen abstraction followed by enolate formation
b. nucleophilic attack by hydroxide on carbonyl carbon followed by hydride transfer
c. aldehyde hydrogen abstraction followed by enolate formation
d. aldehyde hydrogen abstraction followed by hydride transfer
e. a-hydrogen abstraction leading to enolate formation - Answers e
9. Which combination might give an ester that will not be volatile enough to have significant odor?
a. benzyl alcohol and salicylic acid
b. methyl alcohol and formic acid
c. methyl alcohol and acetic acid
d. acetic acid and 2-methyl-1-propanol
e. formic acid and ethyl alcohol - Answers a
10. Which compound will give a positive iodoform test? - Answers CH3C=O group or the CH3CH(OH
aldehyde or ketone
11. The purpose of spotting a mixture of all possible products on the TLC plate is to:
a. identify which product was synthesized by comparing your product to the Rf values from
the mixture
b. demonstrate which products you should have had
c. identify the dinitration product
d. identify any impurities
e. for comparison of the crude product - Answers a
12. Which of the following chemicals will not react with Grignard Reagent?
