Reaction of Alkali Metals with Water

Alkali Metals React with Water

Group 1 metals react vigorously with water produces alkali and hydrogen gas

Group 1 Metals + Water → Alkali + Hydrogen gas

Common Observation

  1. Lithium, sodium or potassium floats and move around on the surface of the water and then dissolve in the water.
    Conclusion:
    Lithium, sodium and potassium are less dense than water.
  2. Colourless gas is released around the metal. The gas produces a “pop” sound when ignited with a lighted wooden splinter.
    Conclusion:
    The colourless flammable gas is hydrogen.
  3. The solution turns blue when it is tested with universal indicator.
    Conclusion:
    the solution produced is an alkali.

Lithium + Water

2Li + 2H2O → 2LiOH + H2

Observation
Lithium metal moves slowly on the surface of the water with ‘fizzing’ sound.

Sodium + Water

2Na + 2H2O → 2NaOH + H2

Observation
The lump of sodium moves swiftly on the surface of the water with ‘fizzing’ sound

Potassium + Water

2K + 2H2O → 2KOH + H2

Observation
Potassium reacts violently with water, move very fast on the surface of the water and burn with a lilac flame.