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Question
A chemical reaction is often accompanied by external indications or characteristics which include –
- Colour change
- Effervescence or gas evolved
- Evolution or absorption of heat
- Formation of a precipitate.
With reference to each of the above indications, state the external indication seen during – Addition of dilute acid to an active metal.
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Solution
Addition of dil. acid to an active metal: Gas is evolved, test tube or flask becomes hot (heat is produced).
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