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प्रश्न
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.
उत्तर
Addition of dil. acid to an active metal: Gas is evolved, test tube or flask becomes hot (heat is produced).
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संबंधित प्रश्न
Complete and balance the following chemical equations
NaCI + `AgNO_3` `→`
Complete and balance the following chemical equations:
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(dil)
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- Colour change
- Effervescence or gas evolved
- Evolution or absorption of heat
- Formation of a precipitate.
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\[\ce{Cl- ->Cl}\]
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\[\ce{H->H+}\]
State whether the following reaction is oxidation or reduction.
\[\ce{Na->Na+}\]
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(b) Rising of hot air over a radiator.
(c) Burning of kerosene in a lantern.
(d) Change the colour of black tea by adding lemon juice to it.
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