Alkynes

Which statement best defines alkynes in organic chemistry?

• Saturated hydrocarbons with single bonds

• Aromatic hydrocarbons with conjugated rings

• Unsaturated hydrocarbons containing C=C bond

• Unsaturated hydrocarbons containing C≡C bond

What is the general molecular formula for a straight-chain alkyne with n carbons?

• CnH2n−2

• CnH2n

• CnH2n+2

• CnHn

Ethyne is the simplest alkyne. Which formula represents ethyne?

• C2H4

• C2H6

• C2H2

• CH4

When one hydrogen is removed from an alkyne, what group is formed, and what is its general formula?

• Alkynyl group, CnH2n−3

• Alkenyl group, CnH2n−1

• Aryl group, CnHn

• Alkyl group, CnH2n+1

Which rule has priority when numbering an alkyne carbon chain?

• Lowest sum of substituent locants

• Alphabetical order of substituents

• Longest chain near the substituent

• Triple bond gets the lowest locant

Refer to the diagram labeled b: What is the correct IUPAC name for the branched alkyne shown?

• 2,4-dimethyl-2-pentyne

• 4-methyl-2-pentyne

• 4-methyl-1-pentyne

• 3-methyl-2-pentyne

Refer to the diagram labeled c: Choose the correct name for the alkyne with chloro and ethyl substituents.

• 5-chloro-3-ethyl-2-hexyne

• 3-chloro-5-ethyl-1-hexyne

• 5-chloro-3-ethyl-1-hexyne

• 5-ethyl-3-chloro-1-hexyne

Refer to the diagram labeled d: What is the correct name for the alkyne with two methyl groups?

• 3,6-dimethyl-4-octyne

• 4,6-dimethyl-3-octyne

• 3,6-dimethyl-3-octyne

• 2,7-dimethyl-4-octyne

Refer to the diagram labeled e: Name the compound with two triple bonds in a five-carbon chain.

• 1,2-pentadiyne

• 2,4-pentadiyne

• 1,3-pentadiyne

• 1,4-pentadiyne

Refer to the diagram labeled f: What is the correct IUPAC name for the branched diyne shown?

• 5-methyl-2,4-heptadiyne

• 5-ethyl-1,3-heptadiyne

• 5-methyl-1,3-heptadiyne

• 3-methyl-1,5-heptadiyne