3.1.11 - Electrode Potentials and Electrochemical Cells (AQA Chemistry)

What happens during a redox reaction?

Electrons move from one atom to another

What happens when electrons move (flow)?

A charge is produced

What are the metal electrodes dipped in?

A solution of their ions

In what direction do electrons flow?

From the negative electrode to the positive electrode

What is EMF or E(cell)?

The difference in voltage between two half-cells

What does EMF stand for?

Electromotive Force

What does an electrode have to be?

A solid that conducts electricity

What electrode would be used if a half-cell didn't contain a solid, i.e. Hydrogen?

Platinum

What sort of reactions occur at each electrode?

Reversible reactions

What does the direction of each reaction depend on?

How easily it is oxidised

How is oxidising ability measured and how?

Using electrode potantials, the more negative the electrode potential the more easily it is oxidised

What symbol do you use to separate subestances in different states?

| (single line)

What symbol do you use to represent the salt bridge?

|| (double line)

How would you write these electrochemical cells shorthand?

Mg (s) | Mg2+ (aq) || Zn2+ (aq) | Zn (s)