Cell Constant and Electrochemical Cells MCQs

Simple electrochemical cells have distinct time constants associated with their operation. The cell time constant represents the duration required for the electrical double layer at a polarizable working electrode to charge or discharge. A basic cell can be seen as a series combination of solution resistance and double-layer capacitance, with the time constant being the sum of these two components. An electrochemical cell, also known as a galvanic cell or voltaic cell, is a device that converts chemical energy into electrical energy.

Which of the following is the strongest reducing agent?

(a) Li
(b) Na
(c) Mg
(d) Ca

Oxygen has a +2 oxidation state in

(a) H₂O
(b) H₂O₂
(c) F₂O
(d) SO₂

When a dilute solution of H2SO4 is electrolyzed using a platinum electrode, at the anode the gas evolved is

(a) SO₃
(b) SO₂
(c) H₂
(d) O₂

The oxidation number of sulfur in Caro’s acid is

(a) +4
(b) +5
(c) +6
(d) +8

When the salt bridge is removed from a cell, its voltage

(a) will increase
(b) will decrease to half
(c) will decrease to zero
(d) will not change

Which of the following is the most powerful reducing agent?

(a) H₂S
(b) H₂SO₃
(c) SnCl₂
(d) HNO₂

Which of the following is not an example of an oxidizing agent?

(a) hydrogen peroxide
(b) potassium dichromate
(c) nitric acid
(d) hydrogen sulfide

Electrolytes conduct electric current

(a) by the movement of ions
(b) by the movement of atoms
(c) by the movement of molecules
(d) by the movement of electrons from the cathode to anode

The reductant may be defined as a substance, whose oxidation number of the atom

(a) increases
(b) decreases
(c) remains constant
(d) may increase or decrease

Which of the following substances can act as both an oxidizing and reducing agent?

(a) KMnO₄
(b) K₂Cr₂O₇
(c) HNO₃
(d) H₂O₂