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Homework Help: Structure & bonding questions

  1. Aug 28, 2010 #1
    1. The problem statement, all variables and given/known data

    A) Potassium Methoxide, KOCH3 has both covalent & ionic bonds...Which are which?

    B) Why do you suppose no one has created a stable cyclopentyne molecule?

    C) How many electrons does a positively charged Carbon atom in a carbocation (C+H3) have? Why is it trigonal planar, and not trigonal pyramidal, like the carboanion?

    2. Relevant equations

    3. The attempt at a solution

    A) Since Potassium has only one electron to share...it would give it up quickly to the Oxygen creating an ionic bond while at the other end, CH3 is covalent.

    B) Cyclopentyne is unstable because the sigma & pi bonds are 180 degrees from the remaining hybrid orbital, which creates a strong repulsion. OR The energy released may blow out the other bonds trying to be made.

    C) I figured 7 electrons, because the charge is 1 positive...but Wikipedia.org says in the intro that it has 6 electrons.
  2. jcsd
  3. Aug 30, 2010 #2


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    Science Advisor

    A) Okay, but you probably need to say something about why the C-O bond is covalent, otherwise you just arrived at it by process of elimination.
    B) Okayish I suppose. Although cyclopentyne has been synthesized. It's stable but reactive if you ask me.
    C) Count the electrons, or draw the lewis structure.
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