CHAPTER 1 - Our Consumer Society Introduces two terms Qualitative Finding what chemicals are present in a substance Quantitative Finding how much each chemicals *Note ? Both these words are similar except for a ?t? and a ?l?. Quantitative is more detaileder analysis then Quanlitative. Because your not just find if a chemical is present, your auctually finding out how much is in there. ?t? is also more detailed then ?l?, so the word with the ?t? (quantitative) is the word that is the more detailed analysis.
CHAPTER 2 ? Identifying Chemicals To identify chemicals we indentify their properties. Color, solubility, melting + frozen temps, etc. These are all Qualitative teqniques.
Common Qualitative Techniques Technique Property the method is based on Used to identify Spectrometry Emission and absorption of light A few metals Flame Tester Group 1+2 metals Atomic Emission 68 metals Atomic Absorption Most metal ions and Colorimetry some simple anions UV-Visible Colored substances Chromatography Absorption onto a stationary An enormous range Paper phase and solubility in a mobile of inorganic + Thin Layer phase organic substances High Performance Liquid Gas-Liquid Electrophoresis Motion of ions of different charges and mass in an electric field FLAME TESTS Flame tests is a way of finding out what metal is present by finding out what color light it emits when heated.
When the metal is heated the electrons get all excited with energy and they jump shells. The electron is now in the ?excited state?. Because they electron wants to return to its original shell, it needs to get rid of all the excess energy. It does this through light energy. Once its let all the energy go through light, it returns to its ?ground? state.
ATOMIC EMISSION SPECTROSCORY Because not all metals give of light energy that is visible to the...