Redox Flashcards
What is standard electrode potential
The EMF of a cell with the given electrode and the standard hydrogen electrode
What substance is used in the salt Bruges
Potassium nitrate
What are electrodes made of in emf
Platinum
What is the purpose of an acid/alkali in a fuel cell
Increase the surface area
Advantages of hydrogen oxygen fuel cells
Only waste water
Less pollution
Greater efficiency than fossil fuel
No recharging
Disadvantages of hydrogen oxygen fuel cells
Need constant fuel supply
Expensive
Hard to safely store hydrogen
Limited lifetime
Use of toxic chemicals in production
Half equation for hydrogen in acid fuel cell
H2 becomes 2H+ and 2e-
Half equation for oxygen in acid fuel cell
O2 + 4H+ + 4e- becomes 2H2O
What is the half equation for hydrogen in an alkali fuel cell
H2 + 2OH- becomes 2H2O + 2e-
What is the half equation for oxygen in an alkali fuel cell
O2 + 2H2O + 4e- becomes 4OH-
What are the E cell values for fuel cells
+1.23V
How does the E cell change between alkali and acid hydrogen fuel cells and why
Does not change as redox reaction is the same
How to calculate e cell value
Take more negative half equation
Reverse it
E cell = E(reduced) - E(oxidised)
Ratio of Fe 2+ to MnO4- in titration
5:1
Ratio of C2O4 2- to MnO4- in titration
5:2
