What is the alkali is the ionic compound, the ionization of the anion is hydroxide (OH-), in fact, the oxygen ion acid root (which can compare sulfur and sulfur), and the anion contains only hydroxide. (Such as LiOH, NaOH, NH3 · H2O) soluble in water, alkaline earth metal ions formed in the periodic table from top to bottom gradually soluble [Be (OH) 2, the alkali metal ions or alkali ions, Mg (OH) 2 is insoluble, Ca (OH) 2, Sr (OH) 2 is slightly soluble, and Ba (OH) 2, Ra (OH) 2 is easily soluble, and other bases are in addition to TlOH and Tl (OH) Is difficult to dissolve alkali and acid metathesis reaction is also known as neutralization reaction, that is, H + + OH- == H2O
