Redox

If one member of the conjugate pair in a half cell is a metal, it is….

Usually used as an electrode

If no solid metal is present in a redox pair…

An inert electrode such as platinum or graphite is used

Cations move towards the

Cathode

Anions move towards the

Anode

How can the direction of electron flow in a galvanic cell be described?

Anode to cathode (OILRIG)

In a galvanic cell, reduction occurs at the…

Positively charged cathode

In a galvanic cell oxidation occurs at the

Negatively charged anode

In a galvanic cell, more reactive substances will be ___ and turned into __

Oxidised; ions

What are the main purposes of a salt bridge?

Completes the circuit and prevents the build-up of charge in half-cells

Electrochemical protection of iron

A method used to prevent corrosion of iron by making it the cathode of an electrochemical cell. This can be achieved by connecting iron to a more reactive metal which corrodes instead.

Oxidation Hints

• Dissolve (atoms lose e- to enter solution as positive ions)

• Corrodes/tarnish

• Burn/ignite

• Evolve gas (element goes from ion to neutral gas molecule by losing e-)

Reduction Hints

• Deposit/precipitate (metal ions gain e- to form solid metal)

• Plated/coated

• Displace (a more active metal pushes a less active metal ion out of solution to reduce it)

• 
  

Species at the top of Standard Electrode Potentials are…

More easily oxidised (so are strong reducing agents)

Limitations of standard electrode potentials

• Assumes 298K

• Assumes 1 bar pressure

• Assumes 1M concentration