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: Some basic chem questions

  1. Jan 30, 2006 #1


    User Avatar

    1. if you want to draw the electron dot structure for say carbon (4 valence electrons) would you draw it with one dot on each side or two on one side, and one on two other sides?

    2. can someone give me a link that helps discuss hybridization - i dont really get it and i need help understanding it and trying to figure it out around central atoms. thanks.
  2. jcsd
  3. Jan 30, 2006 #2
    1. You would put one on each side. You have to add one to each side until you're out of valence electrons so everything is balanced. ^_^

    2. I'm not really sure what that is...
  4. Jan 30, 2006 #3


    User Avatar

    like sp2, sp3, etc...stuff like that.
  5. Feb 1, 2006 #4


    User Avatar
    Science Advisor
    Homework Helper

    most of it is just standard rules. Try to pick up on the main concepts, such as the pauli exclusion principle and apply it. If you're working with VSEPER note that minimizing electron repulsion is one of the main themes.
  6. Feb 1, 2006 #5


    User Avatar

    im pretty good at drawing lewis structures and naming the shapes but i dont quite get how to determine the hybridization around the central atom.
  7. Feb 1, 2006 #6
    It's been a while since I did this but this website gave a decent review on hybridization

    http://chemistry.boisestate.edu/rbanks/inorganic/bonding%20and%20hybridization/bonding_hybridization.htm [Broken]
    Last edited by a moderator: May 2, 2017
  8. Feb 1, 2006 #7
    for determining hybridization, take into account the total electron pairs around the central atom, they maybe bond pairs, or lone pairs, the number of electron pairs is equal to the total number of hybridized orbitals (using pauli's exclusion principle, an orbital can't have more than 2 electrons with opposite spins)

    confused? let's make it all clear with a couple examples

    first we take up NH(3) (Ammonia)

    Now, the central atom in ammonia is nitrogen, which has five valence electrons, three of them are shared by the hydrogens, and two are left unshared.

    So the total number of Electron Pairs? There are 3 bond pairs and a lone pair, which makes the number 4, which means there are four hybridized orbitals.

    Which Hybridization has 4 orbitals? sp3.

    I hope this helps you, if there are any further questions, ask away.
  9. Feb 3, 2006 #8
    i would like to add to aalmighty...............

    this a small technique to calculate the hybridzation quickly.

    for example take [tex]CH_4[/tex],
    add Carbons' 4 valence electrons with the total number of valence electrons in all the hydrogen in the compound and divide by 2 ,


    there four hybrid orbital hence it is sp3

    similarly you can use this technique for other compounds also but when you have Oxygen or bivalent elements in the second place just ignore them and when you have ions take into consideration the no of electrons lost(cations) or gained(anions) by the chemical species.

    here is some table that might help you

    if there are 2 hybrid orbitals it is sp hybridized
    if there are 3 hybrid orbitals it is sp2 hybridized
    if there are 4 hybrid orbitals it is sp3 hybridized
    if there are 5 hybrid orbitals it is sp3d hybridized
    if there are 6 hybrid orbitals it is sp3d2 hybridized
    if there are 7 hybrid orbitals it is sp3d3 hybridized
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook