Electrochemistry Flashcards
Why is a salt bridge used rather then a wire?
To avoid metal/ion potentials in the circuit
Why are K+ and NO3 used?
The ions are stable and will not react.
What side does the more negative half-cell go on?
The left
Where does the most oxidised species go?
Next to the salt bridge
Why is a platinum electrode used?
If the ions in solution are unreactive
Under what conditions does the standard hydrogen electrode have a potential of 0.00V?
1M of H+, 298K and 100kPa.
What is the half cell for the hydrogen electrode?
Pt(s) / H2(aq) / H+ (aq) // ….
What can species on the left oxidise?
Anothing above it on the right
What can any species on the right reduce?
Anything below it on the left
What happens to the EMF is you decrease the concentration?
It becomes more negative
What happens to the EMF is you increase the concentration?
It becomes more positive.
What is the weakest oxidising agent?
The one with the most negative electrode potential
What is the weakest reducing agent?
The one with the most positive electrode potential.
Suggest 2 properties of Pt that make it suitabe for use as an external electrical contact in the cell.
- Conductor
- Inert
Explain why the voltage remains constant in a fuel cell
- Constant supple of reactants
- Concentrations remain constant.
