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ICSE Class 9 Answered

What will be the reaction between metals like sodium, potassium and calcium with cold water?
Asked by Topperlearning User | 28 Sep, 2016, 04:05: PM
answered-by-expert Expert Answer

Metals react with cold water to form metal hydroxide and liberate hydrogen gas.

Sodium        

2Na + 2H2O → 2NaOH + H2↑

The reaction is violent but comparatively less violent than potassium. Sodium melts into a silvery globule and darts about the water.

Potassium

2K + 2H2O → 2KOH + H2↑         

The reaction is violent and exothermic. The heat liberated during the reaction ignites hydrogen.

Calcium 

Ca + 2H2O → Ca(OH)2 + H2↑

The reaction is slightly vigorous, but calcium is quite expensive. Hence, it is economically not viable.

 

Answered by | 28 Sep, 2016, 06:05: PM

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