Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Homework Help: Organic Chemistry - Carbanion Question hybridization/valence/geometry

  1. Jan 16, 2012 #1
    1. The problem statement, all variables and given/known data

    A carbanion is a species that contains a negatively charged, trivalent carbon.

    (a) What is the electronic relationship between a carbanion and a trivalent
    nitrogen compound such as NH3?
    (b) How many valence electrons does the negatively charged carbon atom
    (c) What hybridization do you expect this carbon atom to have?
    (d) What geometry is the carbanion likely to have?

    2. Relevant equations

    4areas of high electron density = sp3 hybridization
    N has 5 valence electrons, C has 4

    3. The attempt at a solution

    a) The N is neutral while the C has a slight negative charge
    b) 8 but so does the N, so why is it negatively charged and not the N
    c) sp3
    d) trigonal pyramidal 107.5
  2. jcsd
  3. Jan 28, 2017 #2


    User Avatar
    Science Advisor
    Gold Member

    The C has a full negative charge. The important point is in part b, as seen below:

    Because the nuclei of C and N do not have the same charge. Two different compounds with the same valence structure are known as isoelectronic, and certain properties such as geometry tend to be very similar between isoelectronic compounds (another example would be CO carbon monoxide and CN-, the cyanide anion).

    Good. This reflects the fact that carbanions are isoelectronic to sp3-hybridized amine nitrogens.

Share this great discussion with others via Reddit, Google+, Twitter, or Facebook

Have something to add?
Draft saved Draft deleted