Class XI, Unit 8: Daniell Cell

What happens when an external potential of 1.1 V is applied to a Daniell cell?

In which direction do electrons flow in the Daniell cell during the redox reaction?

What type of chemical reaction occurs in a galvanic cell like the Daniell cell?

What is the primary function of an electrolytic cell compared to a Daniell cell?

Which statement is true regarding the concentration of Zn2+ and Cu2+ ions in a Daniell cell?

Daniell Cell Overview

Converts chemical energy from redox reactions into electrical energy.
Reaction: Zn(s) + Cu²⁺(aq) → Zn²⁺(aq) + Cu(s) with a potential of 1.1 V at 1 mol dm⁻³ concentration.

Types of Electrochemical Cells

Galvanic/Voltaic Cell: Generates electrical energy from spontaneous reactions.
When an external voltage is applied slowly, the reaction continues until the opposing voltage reaches 1.1 V.
At 1.1 V, the reaction stops, and no current flows.

Electrolytic Cell Function

Increasing external potential beyond 1.1 V reverses the reaction, turning the cell into an electrolytic cell.
This setup uses electrical energy to force non-spontaneous chemical reactions.

Important Concepts

Activity vs Concentration: While activity is preferable to use, in dilute solutions, activity approximates concentration.
Future studies will elaborate on the relationship between activity and concentration.

Components of Daniell Cell

Composed of zinc and copper electrodes immersed in respective salt solutions (ZnSO₄ and CuSO₄).
Electron Flow: Electrons flow from copper to zinc.
Current Flow: Conventional current flows from zinc to copper.
Zinc is deposited at the zinc electrode while copper dissolves from the copper electrode.

This quiz covers the construction and functioning of the Daniell cell, a type of galvanic cell that converts chemical energy into electrical energy through a redox reaction. Participants will explore the principles behind its operation and the electrical potential associated with the cell. Test your understanding of this important electrochemical device!