Reaction of Alkali metals with water.

Generally: 2M(s) + 2H2O(l) → 2M+

(aq) + 2OH-

(aq) + H2(g)

alkali metal + water → alkali metal hydroxide + hydrogen

Observations for the reaction of alkali metal with water:

 Piece of metal floats (alkali metals have low density).

 Piece of metal darts around.

 A hissing sound is heard due to the evolution of a gas.

 If red litmus paper is dipped in the solution, the paper turns blue due to the formation of the

alkali metal hydroxide.

 If few drops of phenolphthalein indicator are added to the water solution turns pink due to the

formation of alkali metal hydroxide.

 If the gas produced is tested with a lit splint, it burns with a squeaky pop sound.