9. Alkenes and Alkynes

Which of the following alkenes is the most stable?

Given the following alkenes: (A) ethene ($C_2{H}_4$), (B) 1-butene ($C_4{H}_8$, terminal), (C) cis-2-butene ($C_4{H}_8$, internal, cis), and (D) 2,3-dimethyl-2-butene (tetrasubstituted), rank them in order of increasing reactivity toward catalytic hydrogenation.

Which of the following alkenes is the most stable?

Which of the following alkenes is expected to be the most stable based on the degree of substitution and hyperconjugation effects?

Which of the following alkenes reacts fastest with $H\mathrm{Cl}$?

When the alkyne ${\mathrm{CH}}_3-C\equiv C-{\mathrm{CH}}_3$ is treated with ozone followed by water, how many carboxylic acid products are formed?

When compound A (2-butanol) is dehydrated using ${\mathrm{POCl}}_3$ and pyridine, which alkene is the major product?

As the chain length of alkynes increases, how are their $vapor pressure$ and $boiling point$ affected?

Which of the following alkenes would you expect to have the lowest heat of hydrogenation?

Given the following alkenes: (A) $\mathrm{CH}{2}_{=}\mathrm{CH}{2}_{}$ (ethylene), (B) $\mathrm{CH}{2}_{=}\mathrm{CHCH}$₃ (propene), (C) $\mathrm{CH}{3}_{}\mathrm{CH}=\mathrm{CHCH}$₃ (cis-2-butene), and (D) $\mathrm{CH}{3}_{}\mathrm{CH}=\mathrm{CHCH}$₃ (trans-2-butene), which of the alkenes above is the least stable (highest in energy)?

Which of the following is the most stable alkene?

Which of the following molecules contains a triple bond?

When $3$-bromo-$3$-methylheptane is treated with a strong base, how many different alkenes (constitutional isomers) can be formed as major products via E$2$ elimination?

Which of the following correctly identifies an appropriate alkyne starting material (a) and the intermediate alkene product (b) in the partial hydrogenation of ${\mathrm{CH}}_3-C_2\equiv C_2-{\mathrm{CH}}_3$ using Lindlar's catalyst?

Which of the following is the correct structure for $3-\mathrm{hex}\mathrm{yne}$?