c8, chemical analysis Flashcards
what is a pure substance
only contains one compound or element throughout, not mixed in with anything else
how can melting or boiling points tell you how pure a substance is
comparing its melting/boiling point to one of a pure substance, the closer the two the purer your sample
what are formulations
formulations are useful mixtures with a precise purpose that are made by following a ‘formula’ (recipe)
each component in a measured quantity
what are the two phases of chromotography
mobile and stationary
what is the mobile phase in chromotography
- where the molecules can move
- always a liquid or gas
what is the stationary phase in chromatography
- where the molecules can’t move
- sold or a really thick liquid
how would you test for chlorine
place damp blue litmus paper on the mouth of the boiling tube
- chlorine will bleach the damp blue litmus paper white
how would you test for oxygen
introduce a glowing splint just inside the test tube and the oxygen will relight it
how to test for carbon dioxide
put bubble gas into the limewater
- causes the solution to turn milky white/ cloudy
how to test for hydrogen
introduce a lit split at the open end of the test tube
- hear a ‘squeaky pop’
what will impurities in a substance do to it’s melting and boiling points
impurities in the sample will lower the mp and increase the bp
resulting in your sample possibly meting and boiling at a range of temperatures
what is a solution
a solute dissolved in a solvent
what is a solute
a substance that is dissolved in a solvent
what is a solvent
a liquid in which chemicals dissolve to make a solution (e.g water, ethanol)
what is chromatography
paper chromatography is a technique for separating components of a mixture between a mobile and a stationary phase
