RP8- Electrochemical Cell

Question 1

What is an electrochemical cell?

Answer 1

2 half cells connected by a salt bridge

Question 2

How do you measure comparative electrode potentials of different metals?

Answer 2

• file a piece of copper
• connect to positive voltmeter terminal
• cut a piece of filter paper saturated in KNO3 and place on top
• connect voltmeter to another piece of metal
• hold against filter paper and record value

Question 3

Why do you need to file away the metal?

Answer 3

• removes oxide layer

Question 4

Outline how you would find the standard electrode potential of an electrode…

Answer 4

• add (mass of) compound
• dissolve in (sulfuric) acid
• transfer to volumetric flask and make up to the mark
• immerse Ti metal in the solution
• connect solutions with salt bridge, through a voltmeter
• record potential difference of cell
• Ecell = Ecopper – Etitanium
• ELHS = ERHS – Ecell OR Ecell should be +1.22 Vif Cu on RHS