This is a picture of the CH4O molecule. It's species is AX4, which is a tetrahedron shape. This means that the bond angles are predicted to be 109.5 degrees, as shown. Arrows with plus signs indicate the polarity of the bonds.
Thursday, February 24, 2011
The CH4O molecule is polar. This means that there is an uneven distribution of the electrons in the molecule. In CH4O, the oxygen that is bonded to the carbon is very electronegative, and the hydrogens that are bonded to the carbon are not very electronegative. This creates a more negative end of the molecule, even though there is a hydrogen bonded to the oxygen. See the picture above so you can visualize this.
The bonds are also polar in nature. Hydrogen has an electronegativity value of 2.2, and carbon has an electronegativity value of 2.5, meaning that the arrow showing the electronegativity difference between the bonds is from the hydrogen to the carbon. This is true for all three hydrogens bonded to the carbon. Oxygen has an electronegativity value of 3.5, making it more electronegative than carbon. Thus the arrow showing polarity would be going from the carbon towards the oxygen. Hydrogen is obviously less electronegative than oxygen, meaning that the arrow would go from hydrogen to the oxygen. All of this is show in the picture above.
Wednesday, February 23, 2011
Two molecules of CH4O adjacent to each other would exhibit all three forces of attraction, London Dispersion Forces, Dipole-Dipole, and Hydrogen Bonding.
London Dispersion Forces is the force of attraction between two molecules created by temporary dipoles, which are caused by the movement of electrons around 2 atoms in a molecule. This force is always present, even between two non-polar molecules.
Two CH4O molecules would also exhibit dipole-dipole, an electrostatic attraction caused by the positive end of one dipole being attracted to the negative end of another dipole. In CH4O, the negative oxygen atom of the molecule would be attracted to one of the Hydrogens of the other.
Hydrogen bonding, the third force of attraction two CH4O molecules would exhibit, is a special case of dipole-dipole in which a temporary covalent bond forms between the Hydrogen of one molecule and the Oxygen, Nitrogen, and Fluorine of an adjacent molecule. In two adjacent molecules of CH4O, a temporary covalent bond could from between any of the four hydrogens of one molecule and the oxygen of the other, either the ones bonded to the carbon or the one bonded to oxygen.
CH4O, also called methanol, is a great molecule! About 10 mL is enough to destroy the optic nerve, causing blindness, and 30 mL is potentially lethal! However, if you really wanted to kill someone with it, you would need about 100-125 mL, which is about 4 fluid ounces. If you're into open wheel racing, CH4O has been used fuel since the 1960s. It burns invisibly, and can be put out with plain water instead of having to use fire suppressants, unlike ethanol fires. If your windshield washer fluid is freezing up, CH4O is also used as an antifreeze in windshield washer fluid. If you're remodeling, methanol is used in wood adhesives. Also, if you need to make a building block for plastics, or maybe a bomb, CH4O is used to manufacture formaldehyde!