3.1.11 Electrode potentials and electrochemical cells (A-level only)

Question 1

What dictates which reaction is oxidisation or reduction in a chemical cell

Answer 1

the More POSITIVE value is reduced
The more NEGATIVE value is oxidised

Question 2

Which out of 2 reactions would make a better oxidising agent

Answer 2

the one with more POSITIVE would make a good oxidising agent

The one with more NEGATIVE would be a better reducing agent

Question 3

what is an electropotential series

Answer 3

a list of electrode potentials in numerical order

Question 4

experiment to find the standard electrode potential of a cell
a metal - hydrogen cell

Answer 4

1. dissolve solid in acid to create solution, including adding it to a volumetric flask
2. set up cell - put the metal electrode in the metal solution, salt bridge to connect the metal beaker to the standard hydrogen cell
   connect the electrodes together by a high resistance voltmeter
3. record voltage of cell

Question 5

half cell reaction of TiO2+(aq) / Ti(s) electrode

Answer 5

TiO2+ + 2H+ + 4e− → Ti + H2O