In a galvanic cell, the salt bridge
- does not participate chemically in the cell reaction
- stops the diffusion of ions from one electrode to another
- is necessary for the occurrence of the cell reaction
- ensures mixing of the two electrolytic solutions
The Correct Option is A
Solution and Explanation
In a galvanic cell, the salt bridge does not participate chemically in the cell reaction. The salt bridge is a device used to provide electrical contact between the two solutions and therefore it completes the electrical circuit. In other words, it connects the oxidation and reduction half-cells of a galvanic cell. It maintains electrical neutrality in both the solutions by a flow of ions.
The ions of the electrolyte present in the salt bridge neither react with the ions of the electrode solutions, nor gets oxidized or reduced at the electrodes. In the absence of salt bridge, the solution in one-half would accumulate positive charge and the other half would accumulate negative charge, which will eventually result in preventing the reaction and thus electricity generation.
Top Questions on Electrochemistry
- The standard reduction potentials are: \[ \mathrm{Cu^{2+} + 2e^- \rightarrow Cu} \quad E^\circ = +0.34\,V \] \[ \mathrm{Zn^{2+} + 2e^- \rightarrow Zn} \quad E^\circ = -0.76\,V \] Calculate the standard cell potential for the reaction: \[ \mathrm{Zn + Cu^{2+} \rightarrow Zn^{2+} + Cu} \]
- BITSAT - 2025
- Chemistry
- Electrochemistry
- The standard electrode potential for Sn\(^{4+}\)/Sn\(^{2+}\) couple is \(+0.15\ \text{V}\) and for Cu\(^{2+}\)/Cu couple is \(+0.73\ \text{V}\). These two couples are connected to make an electrochemical cell. The redox reaction is spontaneous. The cell potential will be:
- CBSE Compartment XII - 2025
- Chemistry
- Electrochemistry
- Which metal reacts most with dilute acid to displace hydrogen?
- AIIMS Paramedical - 2025
- Chemistry
- Electrochemistry
- What is the standard electrode potential of a half-reaction in which electrons are transferred from \(Ag^+\) to \(Ag\)?
- VITEEE - 2025
- Chemistry
- Electrochemistry
- Given below are two statements :
1 M aqueous solution of each of $ Cu(NO_3)_2 $, $ AgNO_3 $, $ Hg_2(NO_3)_2 $; $ Mg(NO_3)_2 $ are electrolysed using inert electrodes, Given : $ E^0_{Ag^+/Ag} = 0.80V $, $ E^0_{Hg_2^{2+}/Hg} = 0.79V $, $ E^0_{Cu^{2+}/Cu} = 0.34V $ and $ E^0_{Mg^{2+}/Mg} = -2.37V $
Statement (I) : With increasing voltage, the sequence of deposition of metals on the cathode will be Ag, Hg and Cu
Statement (II) : Magnesium will not be deposited at cathode instead oxygen gas will be evolved at the cathode.
In the light of the above statements, choose the most appropriate answer from the options given below :- JEE Main - 2025
- Chemistry
- Electrochemistry
Questions Asked in JEE Advanced exam
The reaction sequence given below is carried out with 16 moles of X. The yield of the major product in each step is given below the product in parentheses. The amount (in grams) of S produced is ____.
Use: Atomic mass (in amu): H = 1, C = 12, O = 16, Br = 80- JEE Advanced - 2025
- Organic Chemistry
Let $ a_0, a_1, ..., a_{23} $ be real numbers such that $$ \left(1 + \frac{2}{5}x \right)^{23} = \sum_{i=0}^{23} a_i x^i $$ for every real number $ x $. Let $ a_r $ be the largest among the numbers $ a_j $ for $ 0 \leq j \leq 23 $. Then the value of $ r $ is ________.
- JEE Advanced - 2025
- binomial expansion formula
- The total number of real solutions of the equation $$ \theta = \tan^{-1}(2 \tan \theta) - \frac{1}{2} \sin^{-1} \left( \frac{6 \tan \theta}{9 + \tan^2 \theta} \right) $$ is
(Here, the inverse trigonometric functions $ \sin^{-1} x $ and $ \tan^{-1} x $ assume values in $[-\frac{\pi}{2}, \frac{\pi}{2}]$ and $(-\frac{\pi}{2}, \frac{\pi}{2})$, respectively.)- JEE Advanced - 2025
- Inverse Trigonometric Functions
Let $ \mathbb{R} $ denote the set of all real numbers. Then the area of the region $$ \left\{ (x, y) \in \mathbb{R} \times \mathbb{R} : x > 0, y > \frac{1}{x},\ 5x - 4y - 1 > 0,\ 4x + 4y - 17 < 0 \right\} $$ is
- JEE Advanced - 2025
- Coordinate Geometry
The center of a disk of radius $ r $ and mass $ m $ is attached to a spring of spring constant $ k $, inside a ring of radius $ R>r $ as shown in the figure. The other end of the spring is attached on the periphery of the ring. Both the ring and the disk are in the same vertical plane. The disk can only roll along the inside periphery of the ring, without slipping. The spring can only be stretched or compressed along the periphery of the ring, following Hooke’s law. In equilibrium, the disk is at the bottom of the ring. Assuming small displacement of the disc, the time period of oscillation of center of mass of the disk is written as $ T = \frac{2\pi}{\omega} $. The correct expression for $ \omega $ is ( $ g $ is the acceleration due to gravity):
- JEE Advanced - 2025
- Waves and Oscillations
Concepts Used:
Electrochemical Cells
An electrochemical cell is a device that is used to create electrical energy through the chemical reactions which are involved in it. The electrical energy supplied to electrochemical cells is used to smooth the chemical reactions. In the electrochemical cell, the involved devices have the ability to convert the chemical energy to electrical energy or vice-versa.
Classification of Electrochemical Cell:
Cathode
- Denoted by a positive sign since electrons are consumed here
- A reduction reaction occurs in the cathode of an electrochemical cell
- Electrons move into the cathode
Anode
- Denoted by a negative sign since electrons are liberated here
- An oxidation reaction occurs here
- Electrons move out of the anode
Types of Electrochemical Cells:
Galvanic cells (also known as Voltaic cells)
- Chemical energy is transformed into electrical energy.
- The redox reactions are spontaneous in nature.
- The anode is negatively charged and the cathode is positively charged.
- The electrons originate from the species that undergo oxidation.
Electrolytic cells
- Electrical energy is transformed into chemical energy.
- The redox reactions are non-spontaneous.
- These cells are positively charged anode and negatively charged cathode.
- Electrons originate from an external source.