1.9 Electrode Potentials & Cells Flashcards
What is EMF
Cell potential - the voltage between the two half-cells
The reactions that occur at each electrode are….
reversible
A metal that is easily oxidised has a…
more negative electrode potential
A metal that is easily reduced has a…
more positive electrode potential
Electrode potentials are given in terms of…
reduction
Describe how to draw a shorthand cell
- Use electrode potentials to work out the left and right half-cells
- write out the left hand as oxidation and the right hand as reduction
- write out the reactants and products of the oxidation followed by the reactants and products of the reduction
- Add in a salt bridge by drawing two vertical lines
- Draw a vertical line between reagents in different phases and put a comma between reactants in the same phase
How do you show a salt bridge?
Double vertical line
How do you show reagents in the same phase?
Comma
How do you show reagents in different phases?
Single vertical line
How do you calculate EMF?
right hand side - left hand side
Which side does reduction go on?
right hand side
What conditions are required for measuring standard electrode potentials?
Standard conditions
Why are standard conditions used to measure standard electrode potentials?
So the values can be compared
Describe the standard hydrogen electrode
Hydrogen gas is bubbled through an aqueous solution of H+ ions. A platinum electrode is used as a surface for the redox reactions.
The standard hydrogen electrode potential is always….
show on the left hand side
