Chemistry of Alkali Metals 1. A Simple Synthesis of Liquid K-Na Alloy and Few Examples of its Use in the Chemistry Education Lab

Abstract

Upon pressing small pieces of sodium and potassium with a glass rod, the solid pieces turn into silvery liquid product — a K–Na alloy. The alloy reacts with water very vigorously (often an explosion occurs). This experiment is reserved only for chemistry instructors, providing they take all necessary precautions. Two much safer experiments are described: a novel one, where the alloy is allowed to react with mercury, giving K–Na amalgam, and the reaction of the obtained amalgam with saturated aqueous solution of ammonium chloride, where unstable ammonium amalgam is formed. Ammonium amalgam decays in several minutes to give ammonia, hydrogen and elemental mercury.