How could you tell whether or not a molecule *could* have pi bonds?

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Discussion Overview

The discussion centers on identifying the potential for pi bonds in molecules based on their Lewis structures. Participants explore how to determine the presence of multiple bonds and the implications for pi bonding, with a focus on theoretical understanding and practical drawing of structures.

Discussion Character

  • Conceptual clarification
  • Technical explanation
  • Debate/contested

Main Points Raised

  • One participant suggests that single bonds consist of one sigma bond, while double and triple bonds include pi bonds, indicating that the presence of double or triple bonds in a Lewis structure implies the existence of pi bonds.
  • Another participant questions how to identify multiple bonds from a Lewis structure without redrawing it, seeking clarity on the process.
  • A response emphasizes the necessity of drawing the Lewis structure to ascertain the presence of double or triple bonds.
  • One participant expresses confusion about the need to redraw a Lewis structure if it has already been provided, while also noting the rarity of pi bonds existing in molecules with only single bonds, suggesting a connection to molecular orbital theory.

Areas of Agreement / Disagreement

Participants do not reach a consensus on the methods for determining pi bond potential from Lewis structures, with some advocating for drawing while others question the necessity of this step. The discussion remains unresolved regarding the clarity of identifying multiple bonds without redrawing.

Contextual Notes

Some assumptions about the understanding of Lewis structures and molecular orbital theory are present, but these are not fully articulated. The discussion reflects varying levels of familiarity with the concepts involved.

Jas0n
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Just by looking at its Lewis structure, how could you tell whether or not a molecule could have pi bonds?

Thanks in advance.
 
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This is probably an oversimplified answer, but...Single bonds are made up of 1 sigma bond. Double bonds are made up of 1 sigma and 1 pi bond. Triple bonds are made up of 1 sigma and 2 pi bonds. So if the lewis structure for a molecule has double or triple bonds, it will have pi bonds.
 
Thanks for your reply Cesium, but how do I tell if a molecule has multiple bonds if I'm only given its Lewis structure? Is there a simple way to do so, or do I have to actually draw it out?
 
Yes, you have to draw out the Lewis structure to see if the molecule has double/triple bonds.
 
Jas0n said:
Thanks for your reply Cesium, but how do I tell if a molecule has multiple bonds if I'm only given its Lewis structure? Is there a simple way to do so, or do I have to actually draw it out?
I'm not sure I understand this question. If you've been given the Lewis structure (aka Lewis dot diagram), why would you want to draw it out again?

Jas0n said:
Just by looking at its Lewis structure, how could you tell whether or not a molecule could have pi bonds?
In most cases, you could, as explained by Cesium. It is possible, however, to have pi bonds in a molecule with just a single-bond, but this is quite rare. When you get to molecular orbital theory, you will understand how this is possible.
 

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