chemical analysis (C) Flashcards
what is a pure substance
single element or compound not mixed with any other substance e.g. copper, NACL, CO2
What mixture
contains 2 or more elements or compounds not chemically combined e.g. sea water. air
Boiling points for impure and pure substances
(BPT)
Impure substances have a range of bpt
Pure substances have a specific bpt
Test and results of hydrogen gas
Test: lit splint
Result: squeaky pop noise
Test and result for oxygen gas
Test: glowing splint
Result: relights the glowing splint
Test and result for carbon dioxide
Test: using lime water
Result: clear to cloudy
Test and result for chlorine gas
Test: damp blue litmus paper
Result: bleaches/ goes white
Separation methods (6)
-filtration
-evaporation
-crystallisation
-simple distillation
-fractional distillation
-chromatography
What does each method separate
(Filtration, evaporation, crystallisation, distillation, chromatography
F: insoluble solid from solution
E:Soluble solid from solution
C:soluble solid from solution
SD:solid dissolved in liquid
FD:more than two liquids
CH:colours in dye
Process of chromatography
- draw a line in pencil 1cm above paper
-add ink dot onto the line
-place paper into a solvent in a beaker
-add a lid so liquid doesn’t evaporate
-let solvent travel up the paper
-measure how far the solvent travelled and how far the ink moved
-calculate each Rf value to find which is a match
Process of evaporation
-Measure sulfuric acid into conical flask
-add excess copper oxide into flask and gently heat with bunsen burner until no more copper oxide reacts
-let solution cool and filtrate the solution with filter paper to get any solid copper oxide
-put solution in evaporating basin and gently heat but stop when crystals form
Process of crystallisation
