chem / analysis.mdon commit update practice exams (63f57de)
   1# Chemical Analysis
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   3_Salt - ionic compound formed by acid/base reaction_
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   5## Analysis methods
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   7**Quantitative** - measuring values  
   8**Qualitative** - measuring categories or simple observation of characteristics
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  10### Electrical conductivity
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  12- quick and inexpensive
  13- ionic salts are conductive
  14- measures combined levels of dissolved salts
  15- measured in EC units
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  17### Colorimetry
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  19- e.g. universal indicator (pH), or chlorine analysis
  20- colour levels are compared with standards
  21- colour can be natural or caused by reaction with an added chemical (dye)
  22- instrumental colorimeter - compares subject with samples of known coloration
  23- **complment** of a colour is the colour left after original colour is removed from white light (inverse)
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  25![](graphics/colorimeter.jpg)
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  27### Gravimetric analysis
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  29- precipitates are collected and dried
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  32## Stoichiometry
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  34- analysis of ratios
  35- calculations based on chemical equations
  36- can predict relative amount of substances involved in chemical reactions
  37- chemical equations do not indicate rate or extent of a reaction