Chemical Effects of Electric Current — Class 8 Science NCERT Solutions (Free)

Free step-by-step NCERT solutions for Class 8 Science chapter "Chemical Effects of Electric Current" — 8 important questions with detailed answers for CBSE board exam preparation.

TL;DR: Free step-by-step NCERT solutions for Class 8 Science chapter "Chemical Effects of Electric Current" — 8 important questions with detailed answers for…

By Syllab.in · Updated Jun 14, 2026

Key Questions Covered:

What is electrolysis? Define it and give one example.
What happens at the anode and cathode during electrolysis of water?
Define electroplating. Why is it used?
What are electrolytes? Give two examples.
Why is salt solution a good electrolyte but pure water is a poor electrolyte?
What is the role of an electrolyte in a battery?
+ 2 more questions in the full chapter

Solutions Summary:

Question	Status
What is electrolysis? Define it and give one example.	✓ Solved
What happens at the anode and cathode during electrolysis…	✓ Solved
Define electroplating. Why is it used?	✓ Solved
What are electrolytes? Give two examples.	✓ Solved
Why is salt solution a good electrolyte but pure water is…	✓ Solved
What is the role of an electrolyte in a battery?	✓ Solved

Showing 6 of 8 questions

Q1: What is electrolysis? Define it and give one example.

Electrolysis is the process of decomposing a chemical compound by passing electric current through it. The compound must be in liquid form (molten or solution). Example: Electrolysis of copper sulphate solution produces copper at the cathode and oxygen at the anode. Another example: Water electrolysis produces hydrogen and oxygen gases.

Q2: What happens at the anode and cathode during electrolysis of water?

Anode (positive electrode): Water is oxidized, producing oxygen gas and hydrogen ions. Cathode (negative electrode): Water is reduced, producing hydrogen gas and hydroxide ions. Overall: 2H₂O → 2H₂ (at cathode) + O₂ (at anode). Hydrogen gas is twice the volume of oxygen.

Q3: Define electroplating. Why is it used?

Electroplating is a process of coating a thin layer of one metal onto another metal using electrolysis. Uses: (1) Protect metals from corrosion, (2) Enhance appearance with shiny coating, (3) Prevent rust on iron objects, (4) Improve durability. Objects are dipped in electrolyte solution with the coating metal as anode.

Q4: What are electrolytes? Give two examples.

Electrolytes are substances that conduct electric current in their molten or aqueous solution form. They contain ions that allow current flow. Examples: (1) Copper sulphate solution, (2) Dilute hydrochloric acid, (3) Sodium chloride solution, (4) Battery acid (sulfuric acid). Non-electrolytes like sugar solution do not conduct electricity.

Q5: Why is salt solution a good electrolyte but pure water is a poor electrolyte?

Salt solution contains ions (Na⁺ and Cl⁻) that conduct electric current. Pure water has very few ions and is a poor conductor. When salt dissolves in water, it dissociates into ions, increasing conductivity. Pure water has only H⁺ and OH⁻ ions in trace amounts, making it non-conducting.

Q6: What is the role of an electrolyte in a battery?

The electrolyte in a battery allows ions to flow between the anode and cathode inside the battery. This ion flow completes the internal circuit, enabling electrons to flow through the external circuit. Without an electrolyte, no current can be generated. The chemical reaction in the electrolyte produces the electric energy.

Showing 6 of 8 questions. Visit the full page for complete solutions.