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Ch. 7 - The Reactions of Alkynes • An Introduction to Multistep Synthesis
Bruice - Organic Chemistry 8th Edition
Bruice8th EditionOrganic ChemistryISBN: 9780135213711Not the one you use?Change textbook
Chapter 8, Problem 4f

Draw the condensed and skeletal structures for each of the following:
f. dimethylacetylene

Verified step by step guidance
1
Step 1: Understand the name 'dimethylacetylene'. The term 'acetylene' refers to ethyne (C≡C), which is a molecule with a triple bond between two carbon atoms. 'Dimethyl' indicates that two methyl groups (-CH₃) are attached to the acetylene structure.
Step 2: Determine the placement of the methyl groups. In dimethylacetylene, the two methyl groups are attached to the carbon atoms involved in the triple bond. This results in the structure CH₃-C≡C-CH₃.
Step 3: Draw the condensed structure. The condensed structure is written as CH₃-C≡C-CH₃, where the triple bond is explicitly shown between the two central carbon atoms.
Step 4: Draw the skeletal structure. In the skeletal structure, carbon atoms are represented as vertices, and hydrogen atoms are implied. The triple bond is shown as three parallel lines between the two central carbons, and the methyl groups are represented as branches attached to these carbons.
Step 5: Verify the structure. Ensure that the condensed and skeletal structures accurately represent dimethylacetylene, with the correct number of bonds and atoms. The condensed structure should match CH₃-C≡C-CH₃, and the skeletal structure should visually depict the triple bond and methyl groups.

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Key Concepts

Here are the essential concepts you must grasp in order to answer the question correctly.

Condensed Structures

Condensed structures are a simplified way of representing organic molecules, where atoms are grouped together to show connectivity without depicting all bonds explicitly. In these structures, carbon atoms and their attached hydrogens are often written together, making it easier to visualize the molecular formula and connectivity without drawing every bond.
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Skeletal Structures

Skeletal structures, also known as line-angle structures, represent organic molecules using lines to depict bonds between atoms. Each vertex represents a carbon atom, and hydrogen atoms are usually omitted for clarity. This method is particularly useful for visualizing larger molecules and understanding their geometry and functional groups quickly.
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Alkynes

Alkynes are a class of hydrocarbons characterized by at least one carbon-carbon triple bond. They follow the general formula CnH2n-2 and exhibit unique properties due to the presence of this triple bond, such as increased acidity and reactivity compared to alkenes and alkanes. Dimethylacetylene, specifically, is a symmetrical alkyne with two methyl groups attached to the terminal carbons of the triple bond.
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