Hydrazoic acid was originally prepared by the reaction of aqueous hydrazine with nitrous acid. Other oxidizing agents, such as hydrogen peroxide, nitrosyl chloride, trichloramine or nitric acid, can also be used. In its properties hydrazoic acid shows some analogy to the halogen acids, since it forms poorly soluble (in water) lead, silver and mercury(I) salts. The metallic salts all crystallize in the anhydrous form and decompose on heating, leaving a residue of the pure metal. It is a weak acid (p"K" = 4.75.) Its heavy metal salts are explosive and readily interact with the alkyl iodides. Azides of heavier alkali metals (excluding
Acid–base reaction reacts with an alkali salt (a metal hydroxide), the product is a metal salt and water. Acid–alkali reactions are also neutralization reactions. In general, acid–alkali reactions can be simplified to by omitting spectator ions. Acids are in general pure substances that contain hydrogen cations () or cause them to be produced in solutions. Hydrochloric acid () and sulfuric acid () are common examples. In water, these break apart into ions: The alkali breaks apart in water, yielding dissolved hydroxide ions: Acid–base reaction An acid–base reaction is a chemical reaction that occurs between an acid and a base, which can be