Which Structural Isomer Has the Highest Boiling Point?

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Discussion Overview

The discussion centers around the boiling points of structural isomers, specifically comparing the isomers C-C-C-N and CC(N)C. Participants explore the factors influencing boiling points, including hydrogen bonding and molecular contact area.

Discussion Character

  • Technical explanation
  • Debate/contested

Main Points Raised

  • One participant questions why the isomer C-C-C-N has a higher boiling point than CC(N)C, suggesting that nitrogen's ability to form hydrogen bonds is similar in both cases.
  • Several participants discuss the concept of contact area between molecules, debating whether two pencils or two balls have a larger contact area and how this relates to intermolecular forces.
  • There is a suggestion that the nitrogen in CC(N)C may have less contact area due to the three-carbon chain, which could affect intermolecular attractions.
  • Participants note that hydrogen bonding is just one factor in determining the forces of attraction, and that other intermolecular forces, such as van der Waals forces, also play significant roles.

Areas of Agreement / Disagreement

Participants express differing views on the factors influencing boiling points and intermolecular forces, indicating that the discussion remains unresolved with multiple competing perspectives.

Contextual Notes

Participants do not fully resolve the assumptions regarding the definitions of contact area and the specific contributions of various intermolecular forces to boiling points.

i_love_science
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Homework Statement
There are 4 different isomers of C3H9N. They have boiling points that range from 3°C to 48°C. Identify the isomers that you would expect to exhibit the lowest and highest boiling points. Explain your reasoning in terms of the intermolecular forces involved.
Relevant Equations
structural formulas
Why does the isomer C-C-C-N have the highest boiling point, rather than CC(N)C (where the N is attached to the second carbon)?
Isn't N able to form 3 H-bonds in both cases? Thanks.
 
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What has larger contact area: two pencils, or two balls?
 
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Larger contact area; more Force of attraction, so ...
 
Physics guy said:
Larger contact area; more Force of attraction, so ...
Does the N in CC(N)C has less contact area because of the 3 C chain?
 
i_love_science said:
Does the N in CC(N)C has less contact area because of the 3 C chain?
We are not talking bout the area of a single atom, it does not concern us here. We are trying to identify which of the isomers has larger area to have contact with another molecule. This will cause attraction due to wander walls force. Note that there are also other factors that come into play like Hydrogen bonding etc
 
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Physics guy said:
We are not talking bout the area of a single atom, it does not concern us here. We are trying to identify which of the isomers has larger area to have contact with another molecule. This will cause attraction due to wander walls force. Note that there are also other factors that come into play like Hydrogen bonding etc
So the hydrogen bonding involving N is only one factor determining the force of attraction, other intermolecular forces play an major role as well?
Thanks, I understand now.
 

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