A) Cyclohexane (6-carbon ring, single bonds)

B) Cyclopentene (5-carbon ring, 1 double bond)

C) \(\text{CH}_3\text{—C}\equiv\text{CH}\)

D) Benzene (6-carbon ring, resonance double bonds)

E) \(\text{CH}_2=\text{CH—CH}=\text{CH}_2\)

A) Compound A

B) Compound B

C) Compound C

D) Compound D

E) Compound E

8. Tertiary alcohols are oxidized to ________. 8) ______

A) aldehydes

B) ketones

C) secondary alcohols

D) carboxylic acids

E) none of the above

9. The reaction of butane with oxygen is called ________. 9) ______

A) neutralization

B) substitution

C) combustion

D) titration

E) addition

10. Which one of the following compounds has the smallest number of hydrogen atoms? 10) ______

A) Butane

B) 2-methylpropane

C) Butyne

D) Butene

E) 2-methylbutane

11. What is the IUPAC name for this compound? 11) ______

      O
      ║
CH₃—CH₂—C—CH₂—CH₂—CH₃

A) 3-hexanone

B) 1-methyl-2-pentanone

C) 3-pentanone

D) 4-hexanone

E) 3-hexanal

12. A solution with \([\text{OH}^-]\) of \(5 \times 10^{-3}\) has a pH of ________. 12) ______

A) 5.0

B) 11.7

C) -2.3

D) 7.0

E) 2.3

13. According to Le Châtelier's principle, predict whether adding more \(\text{H}_3\text{O}^+(aq)\) causes the system to shift in the direction of reactants, products, or no change. 13) ______

\(\text{NH}_4^+(aq) + \text{H}_2\text{O}(l) \rightleftharpoons \text{NH}_3(aq) + \text{H}_3\text{O}^+(aq)\)

A) Reactants

B) Products

C) No change

CHEM 1406 Practice Exam 3 Page 2 of 5 (V.B)

CHEM 1406 Practice Exam 3 Section III

14. Identify the Brønsted-Lowry base in the following reaction. 14) ______

\(\text{H}_2\text{O}(l) + \text{CO}_3^{2-}(aq) \rightleftharpoons \text{HCO}_3^-(aq) + \text{OH}^-(aq)\)

A) \(\text{H}_2\text{O}\)

B) \(\text{H}_2\text{CO}_3\)

C) \(\text{HCO}_3^-\)

D) \(\text{CO}_3^{2-}\)

E) \(\text{OH}^-\)

15. Acetone is a ketone commonly used as a ________. 15) ______

A) solvent

B) flavoring agent

C) fuel

D) preservative

E) drain cleaner

16. Which of the following is the weakest acid? 16) ______

A) \(\text{H}_2\text{CO}_3\)

B) \(\text{HCl}\)

C) \(\text{H}_2\text{O}\)

D) \(\text{NH}_4^+\)

E) \(\text{H}_3\text{PO}_4\)

17. In the balanced equation for the complete combustion of heptane, the coefficient for carbon dioxide is: 17) ______

\(\text{C}_7\text{H}_{16}(l) + \text{O}_2(g) \rightarrow \text{CO}_2(g) + \text{H}_2\text{O}(g)\)

A) 6

B) 2

C) 7

D) 4

E) 1

18. Which of the following statements correctly describes the hydronium-hydroxide balance in the given solution? 18) ______

A) In bases, \([\text{OH}^-]\) is less than \([\text{H}_3\text{O}^+]\).

B) In neutral solutions, \([\text{H}_3\text{O}^+] = [\text{H}_2\text{O}]\).

C) In bases, \([\text{OH}^-] = [\text{H}_3\text{O}^+]\).

D) In acids, \([\text{OH}^-]\) is greater than \([\text{H}_3\text{O}^+]\).

E) In bases, \([\text{OH}^-]\) is greater than \([\text{H}_3\text{O}^+]\).

19. The name given to an aqueous solution of HBr is ________. 19) ______

A) font-bold

B) hypobromous acid

C) bromic acid

D) hydrogen bromide

E) bromous acid

20. What is the product of the reaction shown below? 20) ______

\(\text{CH}_3\text{—CH}_2\text{—CH}=\text{CH}_2 + \text{HOH} \xrightarrow{\text{H}^+}\)

A) \(\text{CH}_3\text{—CH(OH)—CH(OH)—CH}_3\)

B) \(\text{CH}_3\text{—CH}_2\text{—C(OH)}=\text{CH}_2\)

C) \(\text{CH}_3\text{—CH}_2\text{—CH(OH)—CH}_2\text{OH}\)

D) \(\text{CH}_3\text{—CH}_2\text{—CH}_2\text{—CH}_2\text{OH}\)

E) \(\text{CH}_3\text{—CH}_2\text{—CH(OH)—CH}_3\)

CHEM 1406 Practice Exam 3 Page 3 of 5 (V.B)

CHEM 1406 Practice Exam 3 Section IV

21. What is the IUPAC name for this compound? 21) ______

    OH
    │
Benzene ring

A) Cyclobenzenol

B) Cyclohexanol

C) Phenol

D) Cyclopentanol

E) Glycerol

22. Ammonium hydroxide is a weak base because ________. 22) ______

A) it dissociates only slightly in water

B) it forms a dilute solution

C) it is only slightly soluble in water

D) it is completely ionized in aqueous solution

E) it is a poor acceptor of protons

23. In a ketone, the carbonyl group is bonded to how many hydrogen atoms? 23) ______

A) None

B) One

C) Two

D) Three

E) Four

24. What is the IUPAC name for this alkane? 24) ______

      CH₂—CH₃
      │
CH₃—CH—CH—CH₂—CH₃
    │
    CH₃

A) 4-ethyl-3-methylpentane

B) 2-ethyl-3-methylpentane

C) 2,3-diethylbutane

D) 3,4-dimethylhexane

E) Octane

25. What kind of attractive forces do alcohols form between individual molecules? 25) ______

A) Carbon bonds

B) Single bonds

C) Oxygen bonds

D) Ionic bonds

E) Hydrogen bonds

26. The name of \(\text{Al(OH)}_3\) is ________. 26) ______

A) aluminum(III) hydroxide

B) aluminum hydroxide

C) monoaluminum trihydroxide

D) aluminum trihydroxide

E) aluminum oxygen hydride

27. Which of the following compounds would give a positive Tollens' test? 27) ______

A) Methanol

B) Acetone

C) Butanal

D) Phenol

E) Diethyl ether

CHEM 1406 Practice Exam 3 Page 4 of 5 (V.B)

CHEM 1406 Practice Exam 3 Section V

28. According to the Brønsted-Lowry definition, ________. 28) ______

A) a base is a proton acceptor

B) an acid is a proton acceptor

C) an acid acts as the solvent

D) a base is a proton donor

E) a base produces \(\text{H}^+\) ions in aqueous solutions

29. The skeletal formula represents what type of alcohol? 29) ______

An OH group attached to a carbon atom, which itself is bonded directly to one benzene ring carbon and two methyl group carbons (total 3 carbons attached to alpha-C).

A) Primary

B) Secondary

C) Tertiary

D) Quaternary

E) None

30. What is the IUPAC name of the following compound? 30) ______

CH₃—CH(CH₃)—CH₂—CH₂—CH=CH₂

A) 2-methyl-1-hexene

B) 5-methyl-2-hexene

C) 1-hexene

D) 2-methyl-5-hexene

E) 5-methyl-1-hexene

🎉 Practice Exam Complete!

Please double-check that all your answers are written clearly in the blank spaces provided on the right-hand side of each question. Use the separate Answer Key & Rationales document to grade your attempt and study the step-by-step solutions.

CHEM 1406 Practice Exam 3 Page 5 of 5 (V.B)

Q10 (Correct: C): Formulas and H counts: Butane (\(\text{C}_4\text{H}_{10}\)), 2-methylpropane (\(\text{C}_4\text{H}_{10}\)), Butyne (\(\text{C}_4\text{H}_{6}\)), Butene (\(\text{C}_4\text{H}_{8}\)), 2-methylbutane (\(\text{C}_5\text{H}_{12}\)). Butyne has the smallest number of hydrogens (6).

CHEM 1406 Exam 3 Explanations Page 1 of 3

CHEM 1406 Teacher Suite

Practice Exam Answer Key & Rationales

Page 2: Questions 11 - 20

Detailed Explanations: Questions 11 - 20

Q11 (Correct: A): Ketone nomenclature: The compound has a 6-carbon chain (hexane parent) with a carbonyl group at carbon 3. This is named 3-hexanone.

Q12 (Correct: B): Given \([\text{OH}^-] = 5.0 \times 10^{-3}\ \text{M}\).
\(\text{pOH} = -\log(5.0 \times 10^{-3}) = 2.30\).
\(\text{pH} = 14.00 - \text{pOH} = 14.00 - 2.30 = \mathbf{11.70}\).

Q13 (Correct: A): According to Le Châtelier's principle, adding more product (here, \(\text{H}_3\text{O}^+\) is a product on the right side) shifts the system back to the left, which is in the direction of the reactants to relieve stress.

Q14 (Correct: D): A Brønsted-Lowry base is a proton acceptor. In the reaction, \(\text{CO}_3^{2-}\) accepts a proton (\(\text{H}^+\)) from water to become bicarbonate (\(\text{HCO}_3^-\)), making \(\text{CO}_3^{2-}\) the base.

Q15 (Correct: A): Acetone is dimethyl ketone. Due to its polar carbonyl group and nonpolar methyl groups, it is miscible with both water and organic hydrocarbons, making it an exceptional solvent.

Q16 (Correct: C): Comparing acid strengths: \(\text{HCl}\) is a strong mineral acid. \(\text{H}_3\text{PO}_4\), \(\text{H}_2\text{CO}_3\), and \(\text{NH}_4^+\) are moderately weak acids. \(\text{H}_2\text{O}\) is amphoteric but has a negligible dissociation constant (\(K_w = 1.0 \times 10^{-14}\)), representing the weakest acid by far.

Q17 (Correct: C): Balancing complete combustion of heptane: \(\text{C}_7\text{H}_{16}(l) + 11\text{O}_2(g) \rightarrow 7\text{CO}_2(g) + 8\text{H}_2\text{O}(g)\). The stoichiometric coefficient of carbon dioxide is 7.

Q18 (Correct: E): By definition, basic solutions have a higher concentration of hydroxide ions than hydronium ions: \([\text{OH}^-] > [\text{H}_3\text{O}^+]\).

Q19 (Correct: A): Binary hydrogen acids are named with the prefix "hydro-", root of nonmetal, and suffix "-ic acid". Hence, aqueous \(\text{HBr}\) is hydrobromic acid. (Note: pure \(\text{HBr}(g)\) gas is named hydrogen bromide).

Q20 (Correct: E): Acid-catalyzed alkene hydration: Adding \(\text{H}_2\text{O}\) (\(\text{H}\) and \(\text{OH}\)) across \(\text{CH}_3\text{—CH}_2\text{—CH}=\text{CH}_2\). By Markovnikov's rule, the \(\text{H}\) adds to the terminal C (C1, with 2 H's) and \(\text{OH}\) adds to the inner C (C2, with 1 H) to yield 2-butanol (\(\text{CH}_3\text{—CH}_2\text{—CH(OH)—CH}_3\)).

CHEM 1406 Exam 3 Explanations Page 2 of 3

CHEM 1406 Teacher Suite

Practice Exam Answer Key & Rationales

Page 3: Questions 21 - 30

Detailed Explanations: Questions 21 - 30

Q21 (Correct: C): An aromatic benzene ring directly bonded to a hydroxyl group is named phenol (benzenol is incorrect under standard IUPAC system naming).

Q22 (Correct: A): Weak bases like ammonium hydroxide are weak because they dissociate or ionize only slightly in water. This establishes an equilibrium where reactants dominate.

Q23 (Correct: A): A ketone carbonyl group is flanked by two alkyl carbons: \(\text{C—C(═O)—C}\). Thus, the carbon atom in the carbonyl group is bonded to zero (none) hydrogen atoms.

Q24 (Correct: D): The parent chain is a continuous 6-carbon chain (hexane). Numbering from either side gives methyl substituents on carbon-3 and carbon-4. Thus, it is named 3,4-dimethylhexane.

Q25 (Correct: E): Alcohols possess a polar \(\text{O—H}\) bond. The highly electronegative oxygen creates strong intermolecular attractive forces called hydrogen bonds with neighboring hydroxyl groups.

Q26 (Correct: B): For metal hydroxides of constant-charge main-group metals (like aluminum, which is always \(3^+\)), Roman numerals are omitted. Thus, \(\text{Al(OH)}_3\) is simply aluminum hydroxide.

Q27 (Correct: C): Tollens' reagent contains silver ammonium ions \([\text{Ag(NH}_3)_2]^+\) which selectively oxidize aldehydes to carboxylic acids, creating a metallic silver mirror. Ketones, alcohols, and ethers do not react. Butanal (an aldehyde) is positive.

Q28 (Correct: A): Under Brønsted-Lowry acid-base definitions: Acids are proton (\(\text{H}^+\)) donors, and bases are proton acceptors.

Q29 (Correct: C): Alcohol classification is based on the number of carbon atoms attached to the carbon bearing the \(\text{—OH}\) group. Because this alpha carbon is bonded directly to three carbons (one phenyl and two methyls), it is classified as a tertiary alcohol.

Q30 (Correct: E): Double-bond takes priority: numbering starts from the right side (\(\text{CH}_2=\text{CH—}\)) making the parent chain 1-hexene. The methyl substituent is located on carbon-5, yielding 5-methyl-1-hexene.

Pedagogical Grading Notes

• Organic (Q1-4, Q6-11, Q15, Q17, Q20-21, Q23-25, Q27, Q29-30): 18 questions total (60% weight).
• Acid-Base (Q5, Q12-14, Q16, Q18-19, Q22, Q26, Q28): 12 questions total (40% weight).
• We recommend grouping raw student errors into these two subsets to identify specific remediation needs before the final.

CHEM 1406 Exam 3 Explanations Page 3 of 3