The electrolytic cell shown below is used for the electrolysis of CuCl2 solution.

A
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----- B
CuCl2 (aq)

A and B are carbon electrodes.

9.1 Define electrolysis.

9.2 Is the process of electrolysis EXOTHERMIC or ENDOTHERMIC?

9.3 Write down the half reaction that occurs at electrode B.

0.369 g of Cu is deposited on the cathode in 27 minutes.

9.4 Calculate the electrical current used during this process.

Electrolysis is an endothermic process where electrical energy drives a non-spontaneous chemical reaction, specifically the reduction of copper ions at the cathode. The half-reaction at electrode B is Cu 2 + + 2 e − → Cu (s) . The current used during this electrolysis process is approximately 0.692 A.
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Answered by SophiaElizab | 2025-07-07

9.1 Define electrolysis.
Electrolysis is a chemical process in which electrical energy is used to drive a non-spontaneous chemical reaction. In an electrolytic cell, this involves passing an electric current through an electrolyte, causing oxidation-reduction reactions at the electrodes and leading to the decomposition of the electrolyte.
9.2 Is the process of electrolysis EXOTHERMIC or ENDOTHERMIC?
Electrolysis is an endothermic process. This means that it requires an input of energy to occur, specifically electrical energy, to drive the chemical reactions that are not naturally spontaneous.
9.3 Write down the half reaction that occurs at electrode B.
In the electrolysis of CuCl 2 ​ (aq), copper ions (Cu 2 + ) are reduced at the cathode. Electrode B is the cathode where the reduction takes place. The half-reaction at electrode B (cathode) is:
Cu 2 + + 2 e − → Cu (s)
This indicates that copper ions in the solution gain two electrons to form solid copper.
9.4 Calculate the electrical current used during this process.
To find the electrical current used, we need to determine the amount of charge involved in depositing 0.369 g of copper and then calculate the current.

Moles of Copper (Cu) deposited:

The molar mass of copper (Cu) is approximately 63.55 g/mol.
Moles of copper deposited = 63.55 g/mol 0.369 g ​ ≈ 0.00581 mol


Charge needed to deposit the copper:

From the reduction half-reaction, one mole of copper (Cu) requires two moles of electrons.
Therefore, charge (Q) in coulombs: Q = 0.00581 mol × 2 mol e − × 96 , 485 C/mol ≈ 1122 C


Calculate the current (I):

Time is given as 27 minutes, which is 27 × 60 = 1620 seconds.
Current I = t Q ​ = 1620 s 1122 C ​ ≈ 0.692 A



Therefore, the electrical current used during this process is approximately 0.692 amperes.

Answered by SophiaElizab | 2025-07-07