electrochem

Question 1

what is the use of Daniell cell

Answer 1

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

Question 2

what happens When Eext > 1.1 V

Answer 2

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.

Question 3

what happens When Eext < 1.1 V in daniell cell

Answer 3

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.

Question 4

what happens When Eext = 1.1 V

Answer 4

When Eext = 1.1 V
(i) No flow of
electrons or
current.
(ii) No chemical
reaction.