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प्रश्न
Give the reason why the following is considered as chemical changes.
A piece of magnesium strip is dropped into a beaker containing dilute hydrochloric acid.
उत्तर
When a piece of magnesium strip is dropped in dilute hydrochloric acid, hydrogen gas is evolved and hence it is a chemical change.
\[\ce{Mg + dil{.} 2HCl -> MgCl2 + H2↑}\]
as new substances, MgCl2 and H2 with new properties are produced and the reaction is irreversible.
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