(c) Would you expect the O—O bond in O₂ to be shorter or longer than the O—O bond in compounds that contain an O—O single bond? Explain.

Verified step by step guidance

1. Understand the concept of bond order: Bond order refers to the number of chemical bonds between a pair of atoms. In molecular oxygen (O2), the bond order is 2, indicating a double bond.
2. Compare bond types: A single bond typically consists of one sigma bond, while a double bond consists of one sigma bond and one pi bond. Double bonds are generally shorter and stronger than single bonds due to the additional pi bond.
3. Consider the bond length: Bond length is inversely related to bond order. Higher bond order usually results in shorter bond lengths because the atoms are held together more tightly.
4. Apply this to O2: Since O2 has a double bond (bond order of 2), the O—O bond in O2 is expected to be shorter than the O—O bond in compounds with an O—O single bond (bond order of 1).
5. Conclude with reasoning: The presence of a pi bond in O2 contributes to a shorter bond length compared to a single bond, which lacks the additional pi bond. Therefore, the O—O bond in O2 is shorter than in compounds with an O—O single bond.

Key Concepts

Bond Order

Bond order refers to the number of chemical bonds between a pair of atoms. In the case of O2, the bond order is 2, indicating a double bond, which typically results in a shorter bond length compared to a single bond. Higher bond orders generally lead to stronger and shorter bonds due to increased electron sharing.

Bond Length

Bond length is the average distance between the nuclei of two bonded atoms. It is influenced by the type of bond (single, double, or triple) and the size of the atoms involved. In general, double bonds (like in O2) are shorter than single bonds due to the stronger attraction between the bonded atoms.

Resonance Structures

Resonance structures are different ways of drawing the same molecule that show the delocalization of electrons. In compounds with O—O single bonds, resonance can affect bond length and strength. However, in O2, the presence of a double bond means that resonance is not a factor, leading to a more stable and shorter bond compared to single-bonded oxygen compounds.