Question

Predict which of the following will be formed at the anode in the electrolysis of an aqueous solution of KI.

a. KI.
b. K
c. O2
d. H2
e. I2

Answer 1

Answer:

e. I2

Explanation:

The  iodide anion ($I^{1-}$) is oxidized to I2 at the anode. One can see by the

appearance of a yellow-brown color in solution which is due to the formation of  triiodide ions.

Answer 2

Answer:

Option e==> I2.

Explanation:

In order for KI to undergo electrolysis it has to be in its molten state or aqueous state because this will enhance the migration of ions. The following reactions and observations occur during the electrolysis of aqueous solution of KI.

(1). At the anode: two reactions are like like to occur that the one in which the I^- is oxidized to give I2 and the one in which oxygen is formed from water but in both above only the case in which I2 is produced is the one that is been observed because of the presence of the violet colour. The equation of Reaction is given below;

2 I^- (aq) -------> I2 (g) + 2 e^-.

Note that the I2 is in gaseous form.

(2). At the cathode : we have two possible Reactions too and the first one is the bubbles which confirms the presence of Hydrogen gas and the second one is the pink colour observed is the presence of OH^-.