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Science (086) — AI-generated practice question

AI-generated practice question — model-generated for extra practice, not a previous-year CBSE board question.

Q1. [1] medium thorough-understanding
Hexane and cyclohexane both contain six carbon atoms. Write their molecular formulae and explain why the two formulae differ, relating your answer to the structural difference between the two compounds.
Generated by claude-sonnet-4-6 · 2026-06-26 01:09 · grounding rag
Model Answer

Hexane: C₆H₁₄; Cyclohexane: C₆H₁₂. Hexane is an open chain (straight chain), so it has 2 extra H atoms compared to cyclohexane, which has carbon atoms arranged in a ring, reducing the hydrogen count by 2.

Source: Carbon and its Compounds, Section 4.2.2

Explanation

The key point is the structural difference: open chain vs. ring. When a chain closes into a ring, two terminal hydrogen atoms are lost to form the extra C–C bond, hence the formula drops from C₆H₁₄ to C₆H₁₂. The examiner wants both formulae stated and a one-line structural reason.

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