Chromatography

Chromatography and Intermolecular Forces By: Courtney The purpose of this page is to describe the influence of intermoleculas forces on the physical and chemical properties of covalent compounds. Chromatography is a way to separate the types of forces, which change the physical properties of covalent compounds.

Types of Intermolecular Forces These are the types of intermolecular forces and their definitions. Physical and Chemical Properties These are the types of properties and their definitions.
 * __Dipole- Dipole Attraction__ is a force that occurs when polar atom line so their positive and negative ends are close to each other.
 * __Hydrogen Bonding__ is form of strong dipole-dipole attraction in which atoms of high electronegative atoms are bonded by hydrogen.
 * __London Dispersion Forces__ is a weak force that occurs among noble gas atoms and nonpolar molecules. This is when there is a temporary dipole-dipole attraction amongst the noble gas atoms and nonpolar molecules.
 * __Physical Properties__ are the characteristics of a substance. During a physical change chemical bonds are not broken.
 * __Chemical Properties__ is the ability of a substance to change into a different substance.

Influence on Physical Properties
 * Hydrogen Bonds: have a high melting point, high surface tension, high heat of vaporization and a low freezing temperature.
 * Dipole-Dipole Attraction: have high melting point, high surface tension, high heat of vaporization and a low freezing temperature.
 * London Dispersion Forces: have low melting point, low surface tension, low heat of vaporization and a high freezing temperature.

Covalent Compounds
 * Compounds in which atoms that are bonded share electrons.

Chromatography
 * Separates mixtures of compounds into individual compounds.
 * Chromatography can be used in the local community and in another form of science. It is used in forensic science to analysis material recovered at a crime scene. The types of materials that forensic scientist use chromatography to detect are: explosives and drugs. Chromatography is useful in the local community because of its ability to be used in forensic science. (Lerner Ed and Lerner Brenda 670)

Work Cited Introductory Chemistry A Foundation by Zumdahl [] [] [] Thin Layer Chromatography." //World of Forensic Science//. Ed. K. Lerner and Brenda Lerner. Vol. 2. Detroit: Gale, 2005. 670. //Gale Virtual Reference Library//. Web. 13 Nov. 2009. []