Sunday, March 6, 2011

Intermolecular forces

Molecules can go through multiple intermolecular forces when coming in contact with the same molecule.  In general an intermolecular force are forces that act between stable molecules or between macromolecules.  These forces are forces that occur between separate covalent molecules.  The force smay be very weak or might be strong such as hydrogen bonding.  These forces hold molecules together. The different types of intermolecular forces are; London dispersion, Dipole, Dipole-Dipole, Dipole induced Dipole, Ionic bonding, and hydrogen bonding.  In this specific case CH4 is non-polar meaning the only forces acting on the molecule when it comes in contact with itself is London dispersion or also known as Van der Waal's force.

Van der Waal's force or London dispersion: This intermolecular force bonds with every two covalent molecules no matter if it is non-polar or polar. In a non-polar molecule elctrons are always moving and mobile.  At any time or instant they might find themselves towards one end of the molecule making that end temporarily negaitve and the other end temporarily positive.  At any time the electrons may have moved up to the other end now reversing the polarity of the molecule.  The force constantly changes the charge of the ends of the molecule.  This is the essence of London dispersion or Vander Der Waal's force.


CH4 has four positivly charged atoms hanging off the central atom.  Since all the atoms are postive the molecules becomes non-polar.  If the atom had unshared elctrons and also postive atoms then the molecular would be polar but in this case the molecular is on-polar.  Now what does non-polar really mean? First off if a molecule is non-polar than it cannot bond with water.  Second being non-polar also means there is no separation of charge, so no postive or negative poles are formed within the molecule.  Lastly if the molecule is non-polar usually the molecule is symmetric.

Ax form of CH4

CH4 or methane has a qunique Ax skeleton form.  An Ax form is the simplest form of a drawing of the molecule.  The A is the central atom while the X is the atoms bonding to the central atom.  In some cases an e exists and that resembles the amount of unshared ecltrons there are. In this case CH4 has the form Ax4.  A molecule with the form Ax4 is made up of 4 equally spaced orbitals forming bonds at angles of 109.5 degrees.  The name for a molecule with the form Ax4 is called a tetrahedral.
Ax4 or tetrahedral
CH4 has four hydrogen atoms connecting to central carbon atom.  There are four bonds occuring throughout this molecule connecting to each of the four valence electrons on the carbon molecule.


CH4 or Methane is a chemical compound with an atomic mass of 16. It is the simplest alkane, and an important component of natural gas. Methane's bond angles are 109.5 degrees between the four hydrogen atoms. Burning methane in the presence of oxygen produces carbon dioxide and water.