Question

Cathode is negative terminal in:
(A) electrochemical cell
(B) electrolytic cell
(C) both electrochemical and electrolytic cells
(D) neither electrochemical nor electrolytic cells

Answer 1

Hint: An electrochemical cell is a device that can generate electric energy from chemical energy, whereas an electrolytic cell is a type of electrochemical cell in which electrical energy is converted to chemical energy.

Complete answer:
Electrochemical cell: this is a device that converts chemical energy to electrical energy. Galvanic cell or voltaic cell
Electrolytic cell: the device which converts electrical energy into chemical energy.

s.no	Electrolytic cell	Electrochemical cell
1	Converts chemical energy into electrical energy	Converts electrical energy into chemical energy
2	An electrochemical cell consists of a cathode(+) and anode (-)	An electrolytic cell consists of a positively charged anode and a negatively charged cathode
3	Chemical energy generates electrical energy with the help of a redox reaction.	Electrical energy brings out a chemical reaction with the help of an external energy source
4	Oxidation takes place at the anode and reduction takes place at the cathode.	Oxidation takes place at the cathode and reduction takes place at the anode.
5	Both the anode and cathode are in different containers known as a half cell, which are connected with a salt bridge.	Both the anode and cathode are in the same container with an electrolyte solution.
6	Used in batteries for example like TV remote batteries	Used in electroplating and purifying copper, gold

From the above differences between electrochemical cell and electrolytic cell, take a look at the 2nd point in an electrolytic cell, “An electrolytic cell consists of a positively charged anode and a negatively charged cathode”. Observe this point that the cathode is a negative terminal in the electrolytic cell, whereas the cathode is a positive terminal in the electrochemical cell. Hence, our question resolved that the cathode is a negative terminal in the electrolytic cell only.
So, the correct answer is “Option B”.

Note: A common example of an electrochemical cell is a standard 1.5 Volt cell which is used to power many electrical appliances such as TV remotes and clocks. The important thing is that an electrolytic cell is one of the types of an electrochemical cell. For example, a lead storage battery which acts as an electrochemical cell while discharging and acts as an electrolytic cell while charging.