Group 1 Metals + Water → Alkali + Hydrogen gas
- 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.
- Colourless gas is released around the metal. The gas produces a “pop” sound when ignited with lighted wooden splinter. Conclusion: The colourless flammable gas is hydrogen.
- The solution turn blue when it is tested with universal indicator. 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.