electrochem Flashcards
what is the use of Daniell cell
This cell converts the chemical energy liberated during the redox reactionto electrical energy and has an electrical
potential equal to 1.1 V when concentration
of Zn2+ and Cu2+ ions is unity (1 mol dm 3)*.Such a device is called a galvanic or a
voltaic cell
what happens When Eext > 1.1 V
When Eext > 1.1 V
(i) Electrons flow
from Cu to Zn
and current flows
from Zn to Cu.
(ii) Zinc is deposited
at the zinc
electrode and
copper dissolves at
copper electrode.
what happens When Eext < 1.1 V in daniell cell
i) Electrons flow from Zn rod to
Cu rod hence current flows
from Cu to Zn.
(ii) Zn dissolves at anode and
copper deposits at cathode.
what happens When Eext = 1.1 V
When Eext = 1.1 V
(i) No flow of
electrons or
current.
(ii) No chemical
reaction.