Advertisements
Advertisements
Question
Why is anode in galvanic cell considered to be negative and cathode positive electrode?
Advertisements
Solution
A galvanic cell works basically in reverse to an electrolytic cell. The anode is the electrode where oxidation takes place, in a galvanic cell, it is the negative electrode, as when oxidation occurs, electrons are left behind on the electrode.
The anode is also the electrode where metal atoms give up their electrons to the metal and go into solution. The electron left behind on it renders it effectively negative and the electron flow goes from it through the wire to the cathode.
Positive aqueous ions in the solution are reduced by the incoming electrons on the cathode. This is why the cathode is a positive electrode because positive ions are reduced to metal atoms there.
APPEARS IN
RELATED QUESTIONS
How many electrons flow through a metllic wire if a current of 0·5 A is passed for 2 hours? (Given : 1 F = 96,500 C mol−1)
E°cell for the given redox reaction is 2.71 V
Mg(s) + Cu2+ (0.01 M) → Mg2+ (0.001 M) + Cu(s)
Calculate Ecell for the reaction. Write the direction of flow of current when an external opposite potential applied is
(i) less than 2.71 V and
(ii) greater than 2.71 V
How many moles of electrons are required for reduction of 2 moles of Zn2+ to Zn?
A solution of Cu(NO3)2 is electrolyzed between platinum electrodes using 0.1 Faraday electricity. How many moles of Cu will be deposited at the cathode?
Can Fe3+ oxidises bromide to bromine under standard conditions?
Given: \[\ce{E^0_{{Fe^{3+}|Fe^{2+}}}}\] = 0.771 V
\[\ce{E^0_{{Br_{2}|Br^-}}}\] = −1.09 V
An electrochemical cell can behave like an electrolytic cell when ______.
Match the items of Column I and Column II.
| Column I | Column II |
| (i) K | (a) I × t |
| (ii) Λm | (b) `Λ_m/Λ_m^0` |
| (iii) α | (c) `K/c` |
| (iv) Q | (d) `G^∗/R` |
Standard reduction electrode potentials of three metals A, B and C are respectively + 0.5 V, – 3.0 V. and – 1.2 V. The reducing powers of there metal is.
On which electrode the oxidation reaction takes place?
In a solution of CuSO4, how much time will be required to precipitate 2 g copper by 0.5 ampere current?
