Determine whether the following pairs of structures are actually different compounds or simply resonance forms of the same compounds.
a.
b.
c.
d.

Verified step by step guidance

1. Step 1: Understand the concept of resonance. Resonance structures are different ways of drawing the same molecule, showing the delocalization of electrons. They are not different compounds but different representations of the same compound.
2. Step 2: Examine the connectivity of atoms in each pair of structures. If the connectivity (the way atoms are bonded to each other) is the same, they might be resonance forms. If the connectivity is different, they are different compounds.
3. Step 3: Look at the placement of electrons, particularly lone pairs and π-bonds. Resonance structures will have the same arrangement of atoms but differ in the placement of electrons.
4. Step 4: Check for charge distribution. Resonance structures can have different distributions of charge, but the overall charge of the molecule should remain the same.
5. Step 5: Consider the hybridization and geometry of the atoms involved. Resonance structures should have the same hybridization and geometry for each atom, as they represent the same molecule.

Key Concepts

Resonance Structures

Resonance structures are different Lewis structures for the same molecule that depict the delocalization of electrons within the molecule. They are used to represent molecules where the electron distribution cannot be described by a single Lewis structure. Resonance structures differ only in the positions of electrons, not in the positions of atoms.

Structural Isomers

Structural isomers are compounds with the same molecular formula but different connectivity of atoms. Unlike resonance structures, structural isomers have different physical and chemical properties because the atoms are connected in different ways, leading to distinct compounds.

Electron Delocalization

Electron delocalization refers to the spreading of electron density across several atoms, which is a key feature in resonance. This concept is crucial for understanding how resonance structures stabilize molecules by allowing electrons to be shared over multiple bonds, reducing the overall energy of the molecule.