Alkali metals react with water vigorously to form hydroxides and dihydrogen . Which of the following alkali metal reacts with water least vigorously ?

Alkali metals react with water vigorously to form hydroxides and dihyd

1.	Alkali metals react with water vigorously to form hydroxides and dihydrogen . Which of the following alkali metal reacts with water least vigorously ?
Answer» Li Na K Cs Solution :Both m.p. and heat of the reaction of alkali metals with `H_(2)O` decreases down the group from Li to Cs . Although the heat of reaction of Li is thehighest but DUE to its high melting POINT , EVEN the heat is not sufficient to melt the METAL thereby exposing greater surface to water for reaction . as a result , Li has the least reactivity by the reactivity increases as the m.p. of the alkali metals decrease down the group from Li to Cs .