Alkynes Knowledge-Based Practice

Questions

1. 1.

   Which of the following compounds is the sole organic product formed when hex-3-yne undergoes ozonolysis followed by treatment with water?

   • A) Hexanoic acid
   • B) Propanal
   • C) Propanoic acid
   • D) Hexan-3-one
2. 2.

   What is the major organic product obtained when propyne is treated with two molar equivalents of hydrogen bromide in the absence of peroxides?

   • A) 1,2-dibromopropane
   • B) 1,1-dibromopropane
   • C) 2,2-dibromopropane
   • D) 1,3-dibromopropane
3. 3.

   Which of the following bases has a sufficiently high basicity to quantitatively deprotonate a terminal alkyne to form an alkynide ion?

   • A) Sodium hydroxide
   • B) Potassium carbonate
   • C) Sodium ethoxide
   • D) Sodium amide
4. 4.

   Which of the following reagents stereoselectively reduces an internal alkyne, such as hex-3-yne, to an (E)-alkene?

   • A) $\text{H}_2$ in the presence of Lindlar's catalyst
   • B) Sodium in liquid ammonia ($\text{Na / liquid NH}_3$)
   • C) Excess $\text{H}_2$ over a platinum catalyst
   • D) Sodium borohydride ($\text{NaBH}_4$) in ethanol
5. 5.

   Which of the following compounds is the major organic product obtained from the hydration of propyne in the presence of dilute sulfuric acid and mercury(II) sulfate?

   • A) Propanal
   • B) Propanoic acid
   • C) 1-Propanol
   • D) Propanone

Answers and step-by-step solutions appear after you finish the test.