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Science (086) — CBSE Class 10 board question

Q1. [1] § 1.1 CHEMICAL EQUATIONS § 1.2 TYPES OF CHEMICAL REACTIONS § 1.2.2 Decomposition Reaction
Answer the following : Give one example each of electrolytic decomposition and decomposition by sunlight.
Previously asked in CBSE board exam
2026 31/1/1 Q26 (c)
Generated by claude-sonnet-4-6 · 2026-06-14 10:34 · grounding rag
Model Answer

Electrolytic decomposition: 2H₂O → 2H₂ + O₂ (electrolysis of water).
Decomposition by sunlight: 2AgCl → 2Ag + Cl₂ (silver chloride decomposes in sunlight).

Explanation

Examiners expect one clear example of each type with a chemical equation. Electrolysis of water is the standard textbook example of electrolytic decomposition; decomposition of AgCl (or AgBr) in sunlight is the standard example of photolytic decomposition. Both are from Chapter 1 of the CBSE Science textbook.

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Previous-year CBSE Grade 10 board exam questions, organised by subject and chapter, each with a model answer — free to read and print.