Science- Scientific Detection

All aspects of Scientific Detection.

For Additional Applied Science.

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  • Created by: Roxy
  • Created on: 29-01-12 16:28

Quantitative: A measure (accurate number) e.g: Colorimetry

Semi Quantative: An estimate (not as accurate as quantitative) e.g: Universal Indicator

Qualitative: A Yes/No answer (no numbers) e.g: Paper Chromatography 

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Electrophoresis


Produces a DNA profile which can:

  • Match to a suspect or victim (crime)
  • *Paternity testing*
  • Pedigree testing
  • Diagnosing genetic disease
  • Identify contents in food

DNA Profiling uses: Electrophoresis and can be used on small biological samples.

*Paternity testing*- Check if a man is the father of a child

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Chromatography

-A method for separating chemical mixtures

 It Analyses loads of unknown mixtures:

  • Banned colours in food
  • Source of pollution in a lake
  • Inks used in a suspected forgery

They're 3 types of chromatography: Paper chromatography, Thin layer chromatography and Gas chromatography.


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Thin layer chromatography and Paper chromatography

  • The dyes are separated by the movement of the solvent (mobile phase) through a medium of filter paper or gel (stationary phase)
  • The dyes move inbetween the mobile and stationary phases as they move up the paper/gel
  • The different dyes move up at different rates- why? They have different solubilities
  • The soluble dyes spend more time in the mobile phase-move up the paper/gel faster than the less soluble who spend more time in stationary phase
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Solutions

Solution-A mixture of a solute and a solvent

Solute- The thing being dissolved

Solvent-The liquid it dissolves in

E.g: Dissolving salt in water-salt is the solute and water is the solvent.

Concentration- Tells you how much solute is dissolved in a volume of solution

Concentration= mass(of solute)/volume(of solution) *(g/cm3)

*g/cm3(cubed)-grams of solute per cm3 of solution

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Comments

luci

THIS IS SO MUCH HELPFUL. IT'S EASY TO UNDERSTAND TO ME

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