Class 12th Chemistry: Electrochemistry

Questions and Answers

What is the process of converting electrical energy into chemical energy?

Electrolysis

Oxidation occurs at the anode.

True

What is the primary application of electrochemical cells?

Generating electricity

Match the following terms with their definitions:

Electrolyte = A substance that facilitates the flow of ions Anode = The electrode at which oxidation occurs Cathode = The electrode at which reduction occurs Electrochemical reaction = A reaction that involves the transfer of electrons Signup and view all the answers

The electrode at which reduction occurs is called the __________.

cathode Signup and view all the answers

What is the purpose of a salt bridge in an electrochemical cell?

To separate the two half-cells Signup and view all the answers

Electrolysis is a spontaneous process.

False Signup and view all the answers

What is the direction of electron flow in an electrochemical cell?

From anode to cathode Signup and view all the answers

The __________ is the electrode at which oxidation occurs.

anode Signup and view all the answers

Match the following terms with their respective electrode processes:

Oxidation = Reduction Anode = Cathode Signup and view all the answers

Study Notes

Electrochemistry

Electrolysis: A process of decomposition of a substance using an electric current.
Electrolyte: A substance that conducts electricity when dissolved in water or melted.
Electrodes: Rods or plates immersed in an electrolyte, through which electric current is passed.

Types of Electrodes

Anode: The electrode at which oxidation occurs, and electrons are lost.
Cathode: The electrode at which reduction occurs, and electrons are gained.

Electrolysis of Water

Hydrogen evolution: The process of hydrogen gas formation at the cathode during electrolysis of water.
Oxygen evolution: The process of oxygen gas formation at the anode during electrolysis of water.
2H2O → 2H2 + O2: The overall reaction of electrolysis of water.

Electrochemical Cell

Galvanic cell: A cell that generates electricity through a spontaneous redox reaction.
Voltaic cell: Another name for a galvanic cell.
Anodic oxidation: Oxidation at the anode in a galvanic cell.
Cathodic reduction: Reduction at the cathode in a galvanic cell.

Daniell Cell

A commercially available galvanic cell: Consists of a copper pot and a zinc rod immersed in a copper sulfate solution.
Zn → Zn2+ + 2e- (at anode) and Cu2+ + 2e- → Cu (at cathode): The half-cell reactions in a Daniell cell.

Nernst Equation

E = E° - (RT/nF) * ln(Q): The equation that relates the cell potential (E) to the standard potential (E°), temperature (T), and reactant concentrations (Q).
E°: The standard potential of a cell at standard conditions (1M concentrations, 298K, 1 atm).
R: The gas constant, T: Temperature in Kelvin, n: Number of electrons transferred, F: Faraday's constant, Q: Reactant concentrations.