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Tuesday, March 1, 2011

Molecular Model

Carbonic Acid is a weak, inorganic acid with the molecular formula H2CO3. It is formed when carbon dioxide is dissolved in water, and only exists as a solution. It is found in sodas, champagne and other "bubbly" drinks. It is found to be corrosive to limerock and calcium, causing the formation of many caves.


Above is a three-dimensional model of a Carbonic Acid molecule. The central atom (gray) is carbon. One oxygen (red) is double-bonded to the carbon, and two other oxygens are single-bonded to it. To each of the oxygens which are single-bonded to the carbon, a hydrogen (white) is also single-bonded.
Carbonic Acid is a AX3 molecule. This means that there are three atoms directly attatched to the central atom, and there are no lone electron pairs on the central atom. AX3 molecules such as carbonic acid take the shape called Triangular planar. Triangular planar molecules form bonds which separate each of the atoms attached to the central atom by 120 degree angles.

Intermolecular Forces

Intermolecular Forces are forces which exist between two molecules which attract them to each other. There are four intermolecular forces which may exist between two molecules, depending on their polarity and the atoms that make up the molecules. These forces are London Dispersion, Dipole-Dipole, Hydrogen bonding, and Dipole-Induced Dipole.
London Dispersion forces exist between every two molecules. They are caused by the movement of electrons between the two molecules, as the movement creates instantaneous, temporary dipoles. It is a very weak force of attraction, and is the only force of attraction between two non-polar molecules.
Dipole-Diople forces exist between two polar molecules. They are caused by the positive dipole of one molecule being attracted to the negative dipole of another. This intermolecular force is stronger than London Dispersion, and exists between two polar molecules.
Hydrogen bonding forces are special cases of dipole-dipole. They are caused by the hydrogen atom of one molecule being attracted to the oxygen, nitrogen or fluorine of another, forming a very strong bond. This intermolecular force is much stronger than both Dipole-Dipole and London Dispersion.
Dipole-Induced Dipole forces exist between one polar and one non-polar molecule. They are caused by an extremely positively or negatively charged molecule attracting another non-polar molecule, despite its even distribution of electrons. This creates an Induced-dipole that is about as weak as London Dispersion.
Three of the four intermolecular forces exist between two Carbonic Acid molecules. These are London Dispersion, as it exists beteween every two molecules, Dipole-Dipole, as Carbonic Acid is a polar molecule with permenant dipoles, and Hydrogen bonding, as Carbonic Acid is a polar molecule which includes both Hydrogen and Oxygen atoms. Dipole-Induced dipole does not exist between two Carbonic Acid molecules, as Carbonic Acid  is a polar molecule, and Dipole-Induced dipole requires one polar and one non-polar molecule.
The diagram above shows the forces of attraction between two Carbonic Acid molecules. The red dotted line between the Hydrogen of one molecule and Oxygen of the other represents Dipole-Diople, while the blue line between the same Hydrogen and Oxygen represents Hydrogen bonding.

Polarity

Molecules are either polar or nonpolar. Polarity is determined by the distribution of electrons throughout the molecule. Polar molecules are those which have an even distribution of electrons (charges) throughout the molecule, while non-polar molecules are those which have an uneven distribution of electrons.
Carbonic Acid is a polar molecule. In the diagram below, it is seen that one end of the molecule is much more negatively charged than the other, as one end includes two positively charged hydrogen and two negatively charged oxygen, while the other only includes one negatively charged oxygen. Therefore, the electron distribution of the atom is uneven, making it a polar molecule.

The bonds between the atoms within molecules are also considered either polar or non-polar. Polar bonds are those between any atom and another atom with a different Electronegativity Value. Non-polar bonds are those between two of the same atoms. All of the bonds in the Carbonic Acid molecule are polar covalent bonds. The arrows in the above diagram show the flow of the energy from the atom with the higher electronegativity value to that with the lower, in each of the bonds. Because all the bonds are polar covalent, each bond has a corresponding arrow.
The bonds between Carbon and Oxygen are represented by taking the absolute value of the difference between the Electronegativity Values of Carbon and Oxygen. This value is 1, which makes the bonds moderately covalent.
The bonds between Oxygen and Hydrogen are represented by taking the absolute value of the difference between the Electronegativity Values of Oxygen and Hydrogen. This value is 1.3, which makes the bonds barely covalent.

What can CARBONIC ACID do for YOU?

H2CO3 may be a weak acid, but its the way you use it that counts!
Carbonic Acid is found in all your favorite sodas! It's used to give it the taste you love, so you always enjoy it!
Over many years, its corrosion of limerock and calcium form beautiful caves! If you're an adventurer, there's no doubt that you'd love caves formed by Carbonic Acid corrosion!

Carbonic Acid even plays a role in the bloodstream, acting as a buffer in the process of respiration - it helps you to breathe correctly!
If you didn't think Carbonic Acid was helpful or necessary, I bet you do now! If you're a fan of any or ALL of these great things, get your CARBONIC ACID today!