Do the line-angle structural formulas in each of the following sets represent (1) the same compound (2) constitutional isomers or (3) different compounds that are not constitutional isomers?
The Correct Answer and Explanation is :
To determine whether the line-angle structural formulas in each set represent the same compound, constitutional isomers, or different compounds that are not constitutional isomers, we need to analyze the connectivity and arrangement of atoms in each structure.
1. Same Compound:
If two structures have the same molecular formula and identical connectivity of atoms, they represent the same compound. Even if the drawings appear different due to rotations or different orientations, the actual connections between atoms remain unchanged.
2. Constitutional Isomers:
Constitutional isomers have the same molecular formula but differ in the connectivity of their atoms. This means the atoms are connected in different orders, leading to distinct compounds with different physical and chemical properties. For example, butanol and diethyl ether both have the molecular formula C₄H₁₀O but differ in their structures and functionalities.
3. Different Compounds That Are Not Constitutional Isomers:
If two structures have different molecular formulas, they are neither the same compound nor constitutional isomers. They are entirely different compounds.
Analyzing the Given Sets:
Without the specific images from the provided link, we can discuss a general approach to analyzing such sets:
- Step 1: Determine the Molecular Formula
- Count the number of each type of atom in each structure to establish the molecular formula.
- If the molecular formulas differ between two structures, they are different compounds.
- Step 2: Analyze Atom Connectivity
- For structures with the same molecular formula, examine the connectivity of atoms.
- If the atoms are connected differently, the structures are constitutional isomers.
- If the connectivity is the same, they represent the same compound, possibly depicted in different orientations.
Example Analysis:
Consider two line-angle structures both with the molecular formula C₅H₁₂:
- Structure A: A straight chain of five carbon atoms (n-pentane).
- Structure B: A chain of four carbon atoms with a methyl group attached to the second carbon (2-methylbutane).
Both structures have the same molecular formula but different connectivity, making them constitutional isomers.
In summary, by determining the molecular formula and analyzing the connectivity of atoms in each structure, we can classify the relationships between different line-angle structural formulas as the same compound, constitutional isomers, or different compounds.