Question
Question: Identify the false statement among the following: A.Oxidation takes place at the positive electrod...
Identify the false statement among the following:
A.Oxidation takes place at the positive electrode in electrolyte cell whereas at negative electrode in voltaic cell.
B.Deposition of metals takes place in both electrolytic cells and galvanic cells.
C.Direction of flow of current is from cathode to anode in electrolytic cells.
D.Both A and B
Solution
We all know about the redox reaction (reduction- oxidation) is a type of chemical reaction which involves the transfer of electrons between two species. In a redox reaction, the oxidation number of a molecule, ions, or atom changes by gain or loss of electrons.
Complete answer:
An electrolytic cell is an electrochemical cell which uses electrical energy to drive a non-spontaneous redox reaction. This electrical energy is generated from the chemical reaction taking place inside the cell.
Now, according to the question,
In an electrolytic cell, it is true that oxidation takes place at positive electrode i.e, anode whereas reduction takes place at negative electrode i.e, cathode, whereas in case of voltaic cell, negative electrode is anode where oxidation takes place and positive electrode is cathode where reduction takes place. So, option A is correct.
Also, in an electrolytic cell, the direction of flow of current is from cathode to anode. So, option C is also correct.
Let’s come to option B i.e. Deposition of metals takes place in both electrolytic cells and galvanic cells. The deposition of metal takes place in only electrolytic cells. Hence option B is incorrect.
The correct answer is option A and C.
Note:
Always remember that in an electrochemical cell, reduction always takes place at cathode and oxidation takes place at anode. You must note a useful mnemonic for remembering the definition for oxidation and reduction i.e. OIL RIG which means Oxidation Is Losing Electron and Reduction Is Gaining Electron. When a substance loses an electron, its oxidation state increases, hence it is oxidized but when a substance gains an electron, its oxidation state decreases. Hence, it is reduced.