Topic 19.1: Electrochemical cells Flashcards
Cell potential definition
Potential difference between two electrodes in a voltaic cell
What does a voltaic cell generate?
Electromotive force
Standard conditions for cell potential
a) 298 K
b) 100 kPa
c) 1 M
Standard cell potential (Formula)
a) E(Cathode) - E (anode)
Standard hydrogen electrode
Half-cell
a) 1 M H+
b) 298 K
c) H2(g) at 100 kPa
d) Pt electrode
Gibbs free energy from cell potential (Formula)
∆G = -nFE
Factors affecting the amount of product in electrolysis
a) Time
b) Current
c) Charge
Reduction of water (Cathode)
2H2O + 2e- => H2 + 2OH-
Oxidation of water (Anode)
2H2O => 4H+ + O2 + 4e-
Possible products of hydrolysis in aqueous solutions in cathode
a) Very reactive metals – H2 (g)
b) Unreactive metals – Production of metals
Possible products of hydrolysis in aqueous solutions in anode
a) Br2 / I2 oxidized rather than H2O
b) SO4 2- / NO3- produce O2(g)
What is produced in the anode at high concentrations of NaCl?
Cl2(g)
What is produced by the electrolysis of CuSO4 using inert electrodes in:
a) Anode
b) Cathode
a) O2
b) Cu
What is produced by the electrolysis of CuSO4 using copper electrodes in:
a) Anode
b) Cathode
a) Copper ions pass into solution
b) Production of copper at the cathode
Definition of electroplating
Process of using electrolysis to deposit a layer of a metal on top of another object
