Question

How do active metals like Sodium, Potassium, and Calcium react with water? Explain your observation.

Answer 1

Active metals like Sodium, Potassium, and Calcium react with cold water to produce hydrogen and sodium hydroxide.

Reaction with sodium
1. The reaction is less vigorous.
2. Sodium melts into silvery globules and darts about Freely on the surface of the water.
$\mathrm{Na}+{\mathrm{H}}_2\mathrm{O}\to \underset{\mathrm{Sodium}\mathrm{hydroxide}}{\mathrm{NaOH}}+{\mathrm{H}}_2$

Reaction with potassium
1. The reaction is violent and exothermic.
2. Heat liberated ignite the hydrogen.
3. Metal burns with a Lilac flame.

$\mathrm{K}+{\mathrm{H}}_2\mathrm{O}\to \underset{\mathrm{Potassium}\mathrm{hydroxide}}{\mathrm{KOH}}+{\mathrm{H}}_2$
Reaction with calcium
1. The reaction is less vigorous
2. The reaction proceeds smoothly to give a steady supply of hydrogen
$\mathrm{Ca}+{\mathrm{H}}_2\mathrm{O}\to \underset{\mathrm{calcium}\mathrm{hydroxide}}{\mathrm{Ca}{\left(\mathrm{OH}\right)}_2}+{\mathrm{H}}_2$