Sunday, January 8, 2012

WELCOME!

Hello and welcome to The Molecule of Chloroform.  This will be a blog all about chloroform.  Everything from its chemical formula, to its molecular structure and beyond.

Introduction

          Chloroform has a chemical formula of CHCl3, which means it is made up of one molecule of Carbon, a molecule of Hydrogen and three molecules of Chlorine.  It is commonly found as a colorless liquid.  It has a pleasant non-irritating odor along with a slightly sweet taste.  Chloroform is considered to be a VOC or volatile organic compound, which means that it can be easily evaporated into the air.  CHCl3 does not burn easily but will at very high temperatures.
          This molecule is a biproduct that is produced when we use chlorine to destroy harmful bacteria found in drinking and waste water.  It is also produced by the chlorination of methane.  Only a small amount of chloroform is produced under these conditions.  Nearly all chloroform made in the United States is created in factories in order to make other chemicals.    Since CHCl3 can easily evaporate it can enter the air directly from chloroform contaminated water and soil.

Structures of Molecule

Above is the lewis structure of Chloroform showing the 109.5 degree angle of a Tetrahedral.  This molecule has the VSEPR form of AX4 (where A represents the central atom, X represents the non-bonded lone pairs).

^This is the lewis structure showing the electron bonds.

^This is a picture of the a lewis structure showing the structure along with the the energy flow going from a lower level of negativity to a higher level of negativity.  It also shows the electronegativity levels of each of the molecules and what kind of bonds hold them together (Covalent or Ionic).
Above is a picture of the electronegativity of each atom being subtracted to show covalence.

3D molecule of Chloroform

Below is the 3D molecular structure of Chloroform




Inter Molecular Forces

Inter Molecular Forces are forces of attraction or repulsion which act between neighboring molecules. London Dispersion, Dipole Dipole, and Hydrogen Bonding are three inter molecular forces.

 London Dispersion- is when electrons in adjacent molecules are located in positions that can give the molecule a temporary pole or charge.  These are also called delta charges and can be positive and negative.

Dipole Dipole- is the attractive end of one molecule and the positive end of another molecule.  This can only take place in a polar (also know as charged) molecule.  Chloroform can also use London Dispersion.

Hydrogen Bonding- is a type of Dipole Dipole that only occurs in some polar molecules.  It is a force that attracts the Hydrogen of one molecule to the Nitrogen, Oxygen or Fluorine of another molecule.
The image above only illustrates Dipole Dipole forces because london Dispersion is an ongoing force.
          Two inter molecular forces that are active between two molecules of CHCl3 are Dipole Dipole, because it is a polar molecule, and London dispersion, because all molecules use them. 
     
       
          CHCl3 does not use Hydrogen bonding because it does no contain the atoms N, O, or F for the Hydrogen to bond to.
The red arrows show the flow of energy from lesser negativity to a higher negativity.  This helps explain that chlorine is a delta negative and Hydrogen is a Delta Positive (delta means temporary charge).  This is why the hydrogen atom in chloroform can bond with one of the chlorine atoms in another chloroform molecule.

Chemistry Tutorial 7.03a: Intermolecular Attractive Forces



This video from http://www.youtube.com/watch?v=xvocI5gG2jg which was created by Mark Rosengarten can help explain all the inter molecular forces.  (It begins explaining polar molecules at about 1 minute and 58 seconds).

Conclusion

          Small traces of chloroform is found in nearly all public drinking water supplies and in the air of all areas of the united states.  The people at a greater risk of being exposed to chloroform are people who work at or near chemical plants, waste water and treatment plants, and paper and pulp mills.  These places are just some of the few that use chloroform in their everyday work.
          CHCl3 can enter your body through the outer epidermis layer (skin), eating or drinking contaminated water, or through inhalation.  This chemical can effect ones health only in high levels or large amounts.  When you are exposed to large amounts, chloroform  your central nervous syrstem, liver and kidneys can all be effected.  It can even cause sores on exposed skin.  Breathing in high levels of chloroform can also cause fatigue, dizziness or headaches.  Yet even with all these side effects it was still one of the first anesthetics to be used during surgery.
          Chloroform has even been found as a link to cause cancer.  This was shown in a study of people who drank contaminated water and then later developed cancer in the colon and urinary bladder.