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

Q1. [1] straightforward initial-understanding
What colour does phenolphthalein turn in a basic solution?
Generated by claude-sonnet-4-6 · 2026-06-17 12:33 · grounding rag
Model Answer

Phenolphthalein turns pink (magenta) in a basic solution.

Source: Acids, Bases and Salts (Chapter 2), Section 2.1.4

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Explanation

Activity 2.6 in the textbook shows that when phenolphthalein is added to NaOH (a base), the solution turns pink. When acid is added and the base is neutralised, the pink colour disappears. Examiners accept either "pink" or "magenta" — both are correct. Do not write "red"; the exact word from the textbook activity is pink.

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