LT#3: Redox Applications

Question 1

How does a galvanic cell (battery) create electricity?

Answer 1

Physically separates the oxidation and reduction reactions and forces the electrons through a wire.

Question 2

What occurs at the Anode of a battery?

Answer 2

The Oxidation half reaction. Electrons are lost by the metal electrode and metal ions enter the solution (electrode gets thinner)

Question 3

What occurs at the Cathode of a battery?

Answer 3

The Reduction half reaction. Metal ions from the solution gain electrons travelling through the wire and form solid metal (electrode gets thicker)

Question 4

That is the purpose of a salt bridge or porous membrane in a galvanic cell?

Answer 4

Keeps the half reactions separate to avoid contamination.

Allows negative ions to move from the solution in the cathode to the anode to complete circuit (negative charges more in complete circle).

Question 5

What happens during Electrolysis and Electroplating?

Answer 5

A non-spontaneous redox reaction is forced to occur by providing the reaction with electricity.

Electrolysis is used to decompose compounds into their elements.

Electroplating creates a thin layer of a metal over top of another metal.

Question 6

Define Rusting

Answer 6

A spontaneous redox reaction involving an exposed metal, water and oxygen.

Question 7

Define Cathodic Protection

Answer 7

Attach a more reactive metal (sacrifical anode) to a metal object that will oxidize first, leaving the other metal unreacted.

The sacrifical anode supplies electrons to the metal object so that it can never be oxidized (lose electrons).

Question 8

What is Galvanization and how does it protect against rusting?

Answer 8

Involves coating iron with a thin coat of Zn. Gives the Fe physical protection (oxygen can’t get to it), but also cathodic protection.