CHAPTER X 

 Acids, Bases, Salts, and Neutralization 



75. Classification of Elements. Elements are divided 

 into two classes: (i) Acid-forming elements and (2) 

 base-forming elements. This division is made according 

 t.o the properties of the elements. 



The basic elements are commonly called metals : iron, 

 copper, silver, and lead are examples. The basic elements 

 form, with H and O, bases or hydroxids, as KOH and 

 NaOH. A^base is a compound composed of a metal in 

 combination with OH, the hydroxyl radical. This radical 

 caiTbe replaced by an acid-forming element. 



An acid is a compound containing hydrogen which 

 can be replaced by a metal. In the preparation of hydro- 

 gen, the H of HC1 was replaced with zinc. The acid-form- 

 ing elements, with hydrogen, and with H and O, form 

 acids. 



Bases and acids are opposite in character and proper- 

 ties. Acids color blue litmus red, bases color red litmus 

 blue. For purposes of study, the different acid- and base- 

 forming elements are subdivided into families and groups 

 which have definite relationships and common character- 

 istics. 



76. Salts. When an acid and a base are brought to- 

 gether, a chemical reaction takes place known as neu- 

 tralization. The product formed by the reaction is a 

 salt. A salt is a compound formed by the union of acid- 



