11 – Standardising a Potassium Permanganate Solution (LC 2027) (Leaving Cert Chemistry): Flashcards
📚Flashcards
Practise the cards
15 cards from this deck
ShowHide
Practise the cards
15 cards from this deck
Standardisation definition
Standardisation definition
Finding exact concentration by titrating against known standard
Standard solution
Standard solution
Substance of known concentration
Why ammonium iron(II) sulfate is good primary standard
Why ammonium iron(II) sulfate is good primary standard
Stable, doesn't absorb moisture, high molar mass
Role of acid when dissolving crystals
Role of acid when dissolving crystals
Prevents oxidation of to
Why excess acid needed in titration
Why excess acid needed in titration
Provides ions for permanganate reduction
Self-indicating meaning
Self-indicating meaning
acts as its own indicator
End point colour in permanganate titration
End point colour in permanganate titration
Permanent faint pink colour
Autocatalysis in this titration
Autocatalysis in this titration
Reaction speeds up as ions form
Mole ratio :
Mole ratio :
1:5
Concordant results requirement
Concordant results requirement
Should agree within 0.1
Brown precipitate indicates
Brown precipitate indicates
Insufficient acid added
Why rinse burette with solution to be used
Why rinse burette with solution to be used
Prevents dilution by residual water
Why can't be made by dilution
Why can't be made by dilution
Concentration changes over time due to decomposition
Oxidation half-equation for
Oxidation half-equation for
Times to invert volumetric flask
Times to invert volumetric flask
About 20 times
