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Question
With reference to Water explain with suitable examples of how the reactivity of the metals could be differentiated.
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Solution
Action of metals with water: K, Na, Ca react with cold water.
K: Darts on the water surface and react violently.
Na: Revolves on the water surface and bums.
Ca: Sinks in water, react less violently.
Hence, K > Na > Ca calcium is less reactive than K and Na.
Mg and Al react with boiling water/steam.
Hence, Mg and Al are less reactive than K, Na, and Ca. Zn, Fe, Pb also react with steam and reaction stops soon. Fe when hot reacts with steam
This shows that Mg > Al > Zn > Fe > Pb.
Cu, Hg, Ag, Pt, Au do not react with steam or even when hot is less reactive.
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