Question

ASSIGNMENT 1
(1) An electrochemical cell was constructed with copper and silver electrodes
i) State which of the electrodes will be
(a). anode (1 mark)
(b) cathode (1 mark)
(c) give reasons for your answer (1 mark)
(d) state the type of reaction occurring at each electrode (2 marks)
(e) write cathodic half-cell equation (2 mark)
(f) write anodic half-cell equation (2 mark)
(g) write a balanced equation for the overall cell reaction (2 mark)
(h) define Galvanic/Voltaic cell (2 mark)
(i) define electrolytic cell (2 mark)

Answer 1

Answer:

(a) Anode : Cu because at anode , half oxidation takes place and Cu is more reactive than Ag so Cu loses electron easily and undergoes oxidation reaction.

(b) Cathode : Ag because at cathode , half reduction reaction takes place and it is less reactive than Cu so it undergoes reduction reaction.

(c) Reason : mentioned above

(d) Cu electrode : half oxidation reaction

Ag electrode : half reduction reaction

(e) half cathodic reaction : ( undergoes reduction)

Ag^+1 (aq) + 1e - Ag(s)

(f) half oxidation reaction: (undergoes oxidation)

Cu(s) - Cu^+2 (aq) + 2e

(g) add both half reactions after balancing the electrons . overall reaction :

2Ag^+1(aq) + Cu(s) - 2Ag(s) + Cu^+2(aq)

(h) Galvanic Cell : The cell which converts the chemical energy ( liberated during the redox reaction ) to electrical energy. In this cell, Spontaneous redox reaction happens.

(i) Electrolytic Cell : The cell converts electrical energy to chemical energy. In this cell, non spontaneous redox reaction happens.