Why do alkali metals react with water?

Question

Mateo Aguilar · Accepted Answer

The alkali metals are all strongly influenced by their #ns^1# valence electron configuration. They are strongly reducing, and very soft or liquid at RT.

Given the #ns^1# configuration, the metals are strongly reducing. Their reaction with water reflects this: #M(s) + H_2O(l) rarr M(OH)(aq) + 1/2H_2(g)# They also exhibit a quantitative reaction with another protic solvent, liquid ammonia: #M(s) + NH_3(l) rarr M(NH_2)(aq) + 1/2H_2(g)# Both in water and (longer-lived) in ammonia, a solvated electron #e^-#, is invoked, and this species is responsible for the brilliant blue colour observed in liquid ammonia. The #ns^1# configuration may also be held responsible for the softness and ductility of the alkali metals, as their propensity to undergo metallic bonding is reduced with respect to other metals, and their melting/boiling points are low. Many labs still have a sodium press, a die with a threaded ram, which can drive the metal through a small hole to produce metres of sodium ribbon.

Wyatt Atkins · Answer

undefined Because they have a single valence electron that is readily lost, alkali metals react with water to form hydroxide ions and hydrogen gas.