Tripple Chemistry practicals
Simple distillation:
- Sample into distillation flask
-
- Heat distillation flask to boiling point of lowest substance
- Vapour rises into condenser where its condsned and collected in
container whilst components of higher bolings points are left behind
Sources for error:
- If bp’s of substances are close this method might produce an impure
product
- Re-distil to ensure purity
Paper chromatography:
- Pencil line near bottom of filter paper (pencil as insoluble)
- Spot ink on line
- Put paper in solvent but solvent bellow the pencil line
- Place watch glass on top of beaker to stop solvent evaporating
- Draw a pencil line at the point where the solvent stops (solvent
front)
- Rf = distance moved by ink spot / solvent front (between 0 and 1)
- The end result is called a chromatogram
, Analysisng a mixture using a combination of separation techniques e.g a
dye:
- First we simply distil to separate the ink from the other liquids
- Then we use paper chromatography on the ink
Investigating neutralisation reactions:
- Measure around 150cm of dilute acid into a conical flask using a
pipette or measuring cylinder
- Measure 0.5g of akali using a mass balance
- Add the alkali to the acid and wait for the base to react completely
- Record pH using either indicator paper or a pH probe
- Repeat adding 0.5g of alkali until all the acid is reacted
Making copper sulfate:
- Warm sulfuric acid in a water bath (reaction rate up)
- Use fume cupboard as acid fumes are toxicf
- Add copper oxide to acid and stir and until excess (copper at bottom
of beaker)
- Filter excess solid out
- This leaeves a copper sulfate solution
- Crystallize
- Leave the solution cool and blue crystlas of pure copper suflate will
form
Using an electrochemical cell:
- Clean two inert electrodes using sandpaper
- Place both electrodes in beaker filled with electrolyte
- Connect inverted test tubes containing aqeuos solution
- Connect electrode to power supply
- As reaction progresses gas will collect in inverted test tubes
Titration:
- Fille bureete with either acid or alkali
- Fill beaker with set volume of the other
- Add an indicator with a sharp colour change (not universal)
- Do a rough titre
- Refill the beaker and bureete and repeat
Simple distillation:
- Sample into distillation flask
-
- Heat distillation flask to boiling point of lowest substance
- Vapour rises into condenser where its condsned and collected in
container whilst components of higher bolings points are left behind
Sources for error:
- If bp’s of substances are close this method might produce an impure
product
- Re-distil to ensure purity
Paper chromatography:
- Pencil line near bottom of filter paper (pencil as insoluble)
- Spot ink on line
- Put paper in solvent but solvent bellow the pencil line
- Place watch glass on top of beaker to stop solvent evaporating
- Draw a pencil line at the point where the solvent stops (solvent
front)
- Rf = distance moved by ink spot / solvent front (between 0 and 1)
- The end result is called a chromatogram
, Analysisng a mixture using a combination of separation techniques e.g a
dye:
- First we simply distil to separate the ink from the other liquids
- Then we use paper chromatography on the ink
Investigating neutralisation reactions:
- Measure around 150cm of dilute acid into a conical flask using a
pipette or measuring cylinder
- Measure 0.5g of akali using a mass balance
- Add the alkali to the acid and wait for the base to react completely
- Record pH using either indicator paper or a pH probe
- Repeat adding 0.5g of alkali until all the acid is reacted
Making copper sulfate:
- Warm sulfuric acid in a water bath (reaction rate up)
- Use fume cupboard as acid fumes are toxicf
- Add copper oxide to acid and stir and until excess (copper at bottom
of beaker)
- Filter excess solid out
- This leaeves a copper sulfate solution
- Crystallize
- Leave the solution cool and blue crystlas of pure copper suflate will
form
Using an electrochemical cell:
- Clean two inert electrodes using sandpaper
- Place both electrodes in beaker filled with electrolyte
- Connect inverted test tubes containing aqeuos solution
- Connect electrode to power supply
- As reaction progresses gas will collect in inverted test tubes
Titration:
- Fille bureete with either acid or alkali
- Fill beaker with set volume of the other
- Add an indicator with a sharp colour change (not universal)
- Do a rough titre
- Refill the beaker and bureete and repeat
