Carbon Tetrachloride
Element is the basic component of the matter. They can be mixed into mixture and react each other and turn into compounds .Compounds consists of two or more different elements and have certain properties. One of them is Carbon tetrachloride. This compound is very useful but it still has many dangers. Therefore, knowing it properties is one important thing in using the compound optimally, orderly and safely. This essay will discuss deeply about this compound.
Carbon Tetrachloride is organic compound with the formula CCl4. This compound also known by many other names like Tetrachloromethane, Benziform, Benzinoform, Carbon chloride, Carbon tet, Freon 10, Halon 104, Methane tetrachloride, Perchloromethane, Tetraform and Tetrasol (Wikipedia, 2012). CCl4 is one of covalent compound and absolutely has covalent bond. Carbon atom, as a central of the molecule, bonds the four chlorine atoms. The carbon atom has four valence electrons, and the chlorine atom has seven valence electrons. In order to follow the octet rule, only one of the seven valence electrons of chlorine is shared to the carbon atom. The bond between carbon and the four chlorine atom is showed by dot Lewis structure below.
The Dot Lewis structure show that four chlorine atoms are positioned symmetrically as corners in a tetrahedral configuration joined to a central carbon atom by single covalent bonds. Because of this symmetrical geometry, CCl4 is non-polar. The molecule model below show the length bond between C and Cl is 1.78Å and the bond angle of each Cl-C-Cl is 109.5° or known as tetrahedral.
Physically, CCl4 is a clear, colorless, sweet odor and non-flammable. It is miscible with most aliphatic solvents and itself is a solvent, the molecular weight is 153.8 g/mol, density is 1.5867 g/cm3 in liquid form, boiling point is 76.7°C, melting point is -23°C, solubility is soluble in acetone, ethanol, benzene and carbon disulfide. CCl4 is very toxic. Drink water that contain CCl4 damages the liver and kidneys. Other symptoms include headache, dizziness, tiredness, weakness and blurred vision. Very high doses can also cause vomiting, stomach pain or death. Breathing carbon tetrachloride may seriously damage the liver and kidneys. Other possible effects are headache or dizziness, tiredness or lightheadedness. Some people breathing carbon tetrachloride seem dazed. Breathing carbon tetrachloride can also cause vomiting and stomach pain. Breathing high doses causes lung damage and death.
CCl4 was originally synthesized by the French chemist Henri Victor Renault in 1839 by the reaction of chloroform with chlorine, but now it is mainly produced from methane (Wikipedia, 2011).
CH4 + 4 Cl2 → CCl4 + 4 HCl
The production often utilizes by-products of other chlorination reactions, such as from the syntheses of dichloromethane and chloroform. Higher chlorocarbons are also subjected to "chlorinolysis:"
C2Cl6 + Cl2 → 2 CCl4
Prior to the 1950s, carbon tetrachloride was manufactured by the chlorination of carbon disulfide at 105 to 130 °C:
CS2 + 3Cl2 → CCl4 + S2Cl2
CCl4 is one of non-polar solvent which generally found as liquid at room temperature. However, in solid form it may be found absolutely by decreasing the temperature. There is transition phase when it is in solid to liquid forms. That phase creates two type of its crystal structure i.e. monoclinic to rhombohedral (Nedelec et all. 1998). Generally the monoclinic and rhombohedral crystal structure shown as follows
Generally the tendency of tetrahedral when it forms crystal structure is become the lattice of its crystal. It means the crystal structure of CCl4 in solid or liquid form is arranged by each molecules of CCl4 symmetrically.
Carbon tetrachloride is used in the synthesis of chlorinated organic compounds, including chlorofluorocarbon refrigerants. It is also used as an agricultural fumigant and as a solvent in the production of semiconductors, in the processing of fats, oils and rubber and in laboratory applications.
Based on the explanation above carbon tetrachloride is very useful but it still has many dangers. Knowing and understanding the chemical and physical properties of CCl4 is one way to wisely take care this compound. Maximize the benefit of CCl4, and minimize the dangers when use it.
REFERENCES
Anonymous. http://en.wikipedia.org/wiki/Carbon_tetrachloride (accessed on 23th February 2012 at 7.20 AM)
Chang, Raymond. 2008. General Chemistry : The Essential Concepts Fifth Edition. New York : Mc Graw Hill
Effendy. 2008. A-Level Chemistry for Senior High School Students Volume 1B. Malang : Bayumedia Publishing
Delaware Health and Social Service. 2009. Carbon Tetrachloride.
Nedelec et all.1998. Crystallization of Carbon Tetrachloride in Confined Geometries. Ecole Nationale Supérieure de Chimie de Clermont Ferrand & Université Blaise Pascal, 24 Avenue des landais 63177 Aubière Cedex, France
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