Structural isomers Knowledge-Based Practice

Questions

1. 1.

   Which of the following hydrocarbons is a positional isomer of pent-2-ene?

   • A) 2-Methylbut-2-ene
   • B) Cyclopentane
   • C) Pent-1-ene
   • D) Pent-2-yne
2. 2.

   Which of the following hydrocarbons is a chain (skeletal) isomer of but-1-ene?

   • A) but-2-ene
   • B) cyclobutane
   • C) 2-methylpropene
   • D) butane
3. 3.

   Which of the following statements is correct regarding the structural isomers pentane, 2-methylbutane, and 2,2-dimethylpropane?

   • A) They have different empirical formulas and percent compositions by mass.
   • B) They have different boiling points because branching alters their molecular surface area.
   • C) They possess identical carbon skeleton connectivity but different spatial orientations.
   • D) They have different molecular masses due to containing different numbers of hydrogen atoms.
4. 4.

   How many structural isomers exist for the alkane with the molecular formula $C_5H_{12}$?

   • A) 2
   • B) 4
   • C) 3
   • D) 5
5. 5.

   Which of the following pairs of hydrocarbons represents a pair of structural isomers?

   • A) Propane and cyclopropane
   • B) Butane and 2-methylpropane
   • C) Pentane and 2-methylpentane
   • D) Cyclopentane and pentane

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