1. Electrode Potentials + Standard Electrode potentials

redox reaction

Reduction and oxidation reactions ocuring at the same time.

salt bridge

a strip of filter paper soaked in KNO3.

why do we use a salt bridge?

This allows ions to flow between the half-cells and balance out the charges, completing the circuit.

what does cell potential or EMF measure and why

A voltmeter is used to measure the voltage between the two half cells.

Electrons flow throughout the wire from the most reactive metal to the least reactive metal.

Electrode potentials

measures how easily a metal is oxidised.

Equation for calculating the cell potential

E cell = E right hand side(reduced) - E left-hand side. (oxidised)

Draw and label the standard hydrogen electrode

page 328

Why do we use platinum for the hydrogen half cell.

There needs to be a solid electrode in order for ions to move around as hydrogen is a gas, and platinum is relatively inert so it won’t react with the hydrogen.

standard conditions for hydrogen electrodes: 3

• Any solution of ions must have a concentration of 1.00 mol dm-3

• temperature must be 298K (25 degrees Celsius)

• 100kPA for pressure

standard electrode potential definition

The standard electrode potential of a half-cell is the voltage measured under standard conditions when the half-cell is connected to a standard hydrogen electrode.