Chapter 23 - Redox And Electrode Potentials Flashcards
Define redox
A reaction in which both reduction and oxidation take place.
Define oxidation
The loss of electrons or an increase in oxidation number.
Define reduction
The gain of electrons or a decrease in oxidation number.
What is the Manganate half reaction?
MnO(4)- + 8H+ + 5e- -> Mn2+ + 4H(2)O
What is the iodine sodium thiosulphate reaction?
2S(2)O(3)2- + I(2) -> S(4)O(6)2- + 2I-
Why is there no clear colour change at the end point of a Vanadium and Potassium Manganate titration?
KMnO(4) is purple/pink
V2+ is violet
What property does the voltmeter have in a cell?
High resistance
Which way does the current flow in the cell?
Negative electrode to the positive electrode
How do the ions flow between cells?
Salt bridge
What is the salt bridge generally made of?
Potassium nitrate
Ammonium nitrate
What is the electrode made of in a standard hydrogen cell?
Platinum
What is in the half cell of Fe3+ and Fe2+?
Inert Pt electrode
Equimolar Fe2+ and Fe3+ (1 mol dm^-3)
When two half cells are connected, which is oxidised and which is reduced?
More reactive metal is oxidised
Less reactive metal is reduced
Define standard electrode potential
The emf of a half cell compared with a standard hydrogen half cell, measured at 298K with solution concentrations of 1 mol/dm^3 and a gas pressure of 101kPa.
What is the electrode potential of a hydrogen half cell?
0.00V
