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Ch.20 - Organic ChemistryWorksheetSee all chapters
All Chapters
Ch.1 - Intro to General Chemistry
Ch.2 - Atoms & Elements
Ch.3 - Chemical Reactions
BONUS: Lab Techniques and Procedures
BONUS: Mathematical Operations and Functions
Ch.4 - Chemical Quantities & Aqueous Reactions
Ch.5 - Gases
Ch.6 - Thermochemistry
Ch.7 - Quantum Mechanics
Ch.8 - Periodic Properties of the Elements
Ch.9 - Bonding & Molecular Structure
Ch.10 - Molecular Shapes & Valence Bond Theory
Ch.11 - Liquids, Solids & Intermolecular Forces
Ch.12 - Solutions
Ch.13 - Chemical Kinetics
Ch.14 - Chemical Equilibrium
Ch.15 - Acid and Base Equilibrium
Ch.16 - Aqueous Equilibrium
Ch.17 - Chemical Thermodynamics
Ch.18 - Electrochemistry
Ch.19 - Nuclear Chemistry
Ch.20 - Organic Chemistry
Ch.22 - Chemistry of the Nonmetals
Ch.23 - Transition Metals and Coordination Compounds
Introduction to Organic Chemistry
Structural Formula
Optical Isomers
The Alkyl Group
Naming Alkanes
Naming Alkenes
Naming Alkynes
Alkane Reactions
Alkenes and Alkynes
Benzene Reactions
Functional Groups
Alcohol Reactions
Carboxylic Acid Derivative Reactions

Like the other hydrocarbons, the alkynes also have a list of rules they must follow for naming. 

Naming Alkynes

Concept #1: Rules for naming Alkynes


Hey guys! In this new video, we're going to take a look at naming alkynes. Naming alkynes is very similar to naming alkenes. Here we have to find the longest carbon chain, but now we change the -ane to -yne because we’re dealing with an alkyne. We change the -ane ending to -yne. Here, if there's more than one longest chain, go with the one that gives you more substituents. Just like with alkenes, here we’re going to count from the end closest to the triple bond and we have to state numerically where that triple bond starts.
Then with substituents, if there are same kinds of substituents around, then we talk about numerical prefixes. We’re talking about di, tri, tetra, and penta. Actually, let's take a look at this first one right now. Then I'll let you guys attempt example 2 on your own. Here: Name the following alkyne compound. Just like before, what I want you guys to do is look for the longest carbon chain.
And then remember, count from the end closest to the triple bond. Anything that's not part of the longest carbon chain is an alkyl substituent. Name that in the beginning of the name. State its location. State the location of the triple bond and you'll have the name of your structure. So guys, attempt to do this one. Come back and take a look at the video. Go over how exactly we name this first compound.

Example #1: Naming the following alkyne compound. 


Alright guys! Let's attempt to name that example dealing with that alkyne structure. Hopefully, you were able to see that the longest carbon chain was this carbon chain and that we want to number from the end closest to the triple bond. That's 1, 2, 3, 4, 5, 6. We're going to stay here that we have a methyl group on carbon number 4. The name you should have gotten was 4-methyl. The triple bond starts after carbon 2, so 2-hex and it's no longer -ane. We change the -ane to -yne, so hexyne. That's the name you should have gotten.
Now that we've done this, attempt to do this one here. Here I'm going to give you guys a lot of help. When we say phenyl, phenyl is when benzene is a substituent. Benzene as a substituent. Recall, what does benzene look like again? How exactly does it fit into this compound? Start with the end of the name to help you draw it. Come back and see how I draw this compound.

Example #2: Provide the structural formula from the following alkyne name.