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.
  2. Conclusion: Lithium, sodium and potassium are less dense than water.
  3. Colourless gas is released around the metal. The gas produces a “pop” sound when ignited with lighted wooden splinter.
  4. Conclusion: The colourless flammable gas is hydrogen.
  5. The solution turn blue when it is tested with universal indicator.
  6. Conclusion: the solution produced is an alkali.

Lithium + Water

2Li + 2H2O → 2LiOH + H2

Lithium metal moves slowly on the surface of water with 'fizzing' sound.

Sodium + Water

2Na + 2H2O → 2NaOH + H2

The lump of sodium moves swiftly on the surface of water with 'fizzing' sound

Potassium + Water

2K + 2H2O → 2KOH + H2

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


Post a Comment