Redox Titrations Flashcards
1
Q
Colour change of potassium permanganate(VII) when reduced
A
From purple when 7+ to pink when Mn2+
2
Q
Colour change of Fe2+ when oxidised
A
Very pale green when Fe2+ to very pale yellow when 3+
3
Q
Equation for reaction between Fe2+ and MnO4 -
A
5Fe2+ + MnO4 - + 8H+ —> 5Fe3+ + Mn2+ + 4H2O
4
Q
What occurs at end point when MnO4- added to Fe2+
A
When all Fe2+ used up there is excess MnO4 - so pale pink comour
5
Q
What happens if insufficient acid added to Fe2+ and MnO4- titration
A
Titre value higher and brown precipitate of MnO2 forms so MnO4- not fully reduced
