August 18, 2019, 03:36:24 PM
Forum Rules: Read This Before Posting


Topic: c-c-c-c why does carbon easily form chains?  (Read 2070 times)

0 Members and 1 Guest are viewing this topic.

Offline fluidityt

  • Very New Member
  • *
  • Posts: 2
  • Mole Snacks: +0/-0
c-c-c-c why does carbon easily form chains?
« on: January 27, 2013, 06:04:42 PM »
Greetings!
an example of my question: butane

wouldnt it be easy to break the carbon chains (as in a polar or ionic bond, similar to salt in water)? why does none of the hydrogen get in between the carbon?

 I know that H and C are both trying to receive or donate electrons to form strong bonds.

it seems that carbon likes to stick to carbon, regardless of electronegativity. which doesnt make sence... hence why I am asking here =]


another example would be oxygen and nitrogen forming groups with carbon, though, not disrupting the carbon bonds.

thanks for reading my question and for your time.
« Last Edit: April 16, 2018, 02:38:46 PM by Arkcon »

Offline Arkcon

  • Retired Staff
  • Sr. Member
  • *
  • Posts: 7360
  • Mole Snacks: +533/-146
Re: c-c-c-c why does carbon easily form chains?
« Reply #1 on: January 27, 2013, 07:48:53 PM »
Briefly, carbon forms long chains better than any other element because carbon's last valence p-shell is the least diffuse. http://en.wikipedia.org/wiki/Catenation
Hey, I'm not judging.  I just like to shoot straight.  I'm a man of science.

Offline curiouscat

  • Chemist
  • Sr. Member
  • *
  • Posts: 3005
  • Mole Snacks: +121/-35
Re: c-c-c-c why does carbon easily form chains?
« Reply #2 on: January 27, 2013, 11:49:00 PM »
Quote
wouldnt it be easy to break the carbon chains

No.

C-C bonds are typically very hard to break.

Offline orgopete

  • Chemist
  • Sr. Member
  • *
  • Posts: 2636
  • Mole Snacks: +213/-71
    • Curved Arrow Press
Re: c-c-c-c why does carbon easily form chains?
« Reply #3 on: January 28, 2013, 02:47:25 PM »
This is a complicated question and therefore difficult to give a simple answer to. If you had followed my past arguments or attended my talk about electronegativity at the Philadelphia ACS meeting, then you might know Pauling was trying to explain atomic reactivity. Simply, fluorine is the most reactive element (as an electron acceptor), hence most electronegative. Oxygen is the second most reactive, not chlorine, bromine, or iodine. Carbon is an intermediate atom between an electron donor and acceptor and is very effective being able to share electrons.

The reactivity of carbon or butane should be placed in context of reactivity. Will or can it react with another element and release energy as a result? Ethylene or acetylene can react with hydrogen to give ethane plus heat. This teaches us about the relative energy levels of those forms of carbon and hydrogen. Butane does not react with hydrogen to give a new compound and release heat. Butane will react with oxygen or fluorine to give new compounds plus heat. Thus even though carbon-carbon bonds are stable to hydrogen or carbon, they are less stable than C-F, C-O, H-F, or H-O bonds.

This is not necessarily a reflection of the stability of carbon-carbon or carbon-hydrogen bonds per se, but it is also a reflection of the reactivity of oxygen and flourine. Perhaps a measure of bond stability might be compared with the energy required to form a new bond. It is relatively easy to form new carbon-carbon bonds, but relatively difficult to reform flourine, hydrogen, or oxygen from other combinations. if thought of in this way, we could recognize that carbon is good at sharing electrons in chemical bonds, but also capable of forming new bonds with very reactive elements.

In my talk, I showed two charts of the same reaction. Typically, the convention is to calculate the energy differences from the elements (set at zero). This makes HF seem very stable. If plotted with the products as arriving at the same energy levels, then flourine appears to start with the greatest energy. This is the core of electronegativity. If the posters question is considered from this perspective, then it is not a question of electronegativity that determines the stability of carbon bonds, rather the inate properties of carbon. Carbon is stable because it is stable. It can only react with something more reactive than itself.
Author of a multi-tiered example based workbook for learning organic chemistry mechanisms.

Offline fluidityt

  • Very New Member
  • *
  • Posts: 2
  • Mole Snacks: +0/-0
Re: c-c-c-c why does carbon easily form chains?
« Reply #4 on: January 29, 2013, 11:03:47 PM »
This is a complicated question and therefore difficult to give a simple answer to. If you had followed my past arguments or attended my talk about electronegativity at the Philadelphia ACS meeting, then you might know Pauling was trying to explain atomic reactivity. Simply, fluorine is the most reactive element (as an electron acceptor), hence most electronegative. Oxygen is the second most reactive, not chlorine, bromine, or iodine. Carbon is an intermediate atom between an electron donor and acceptor and is very effective being able to share electrons.

The reactivity of carbon or butane should be placed in context of reactivity. Will or can it react with another element and release energy as a result? Ethylene or acetylene can react with hydrogen to give ethane plus heat. This teaches us about the relative energy levels of those forms of carbon and hydrogen. Butane does not react with hydrogen to give a new compound and release heat. Butane will react with oxygen or fluorine to give new compounds plus heat. Thus even though carbon-carbon bonds are stable to hydrogen or carbon, they are less stable than C-F, C-O, H-F, or H-O bonds.

This is not necessarily a reflection of the stability of carbon-carbon or carbon-hydrogen bonds per se, but it is also a reflection of the reactivity of oxygen and flourine. Perhaps a measure of bond stability might be compared with the energy required to form a new bond. It is relatively easy to form new carbon-carbon bonds, but relatively difficult to reform flourine, hydrogen, or oxygen from other combinations. if thought of in this way, we could recognize that carbon is good at sharing electrons in chemical bonds, but also capable of forming new bonds with very reactive elements.

In my talk, I showed two charts of the same reaction. Typically, the convention is to calculate the energy differences from the elements (set at zero). This makes HF seem very stable. If plotted with the products as arriving at the same energy levels, then flourine appears to start with the greatest energy. This is the core of electronegativity. If the posters question is considered from this perspective, then it is not a question of electronegativity that determines the stability of carbon bonds, rather the inate properties of carbon. Carbon is stable because it is stable. It can only react with something more reactive than itself.

Very interesting! I'm still new to chemistry and have not even begun to fathom of what you speak. You seem to edify my novice realization that there is more than EN at play in regards to bonding and sharing/donating =]


Thanks for the response!

Sponsored Links