76 AGRICULTURAL CHEMISTRY 



salt always contains H, a metal, and a radical. HNaSO 4 

 is acid sodium sulfate, as only one H atom has been 

 replaced with Na. A normal salt contains no replace- 

 able H. 



83. Basicity of Acids Acids with one replaceable H 

 atom are called monobasic acids, as HC1 and HNO 3 . 

 Acids with two H atoms are dibasic, as H 2 SO 4 , H 2 SiO 3 , 

 and H 2 CO 3 . When an acid contains three replaceable H 

 atoms, it is tribasic, as H 3 PO 4 . 



84. Two Series of Salts. When a base element has 

 more than one valence, it forms two series of salts. For 

 example, Fe has a valence of 2 and 3. The first series 

 of salts is known by the ending ous. The second series 

 has an ic ending. The one ending means that the com- 

 pound is formed from the lower valence of the element, 

 as FeCl 2 , ferrous chlorid, while FeCl 3 is called ferric 

 chlorid. There are two series of copper salts ; CuCl is 

 called cuprous chlorid, and CuCl 2 , cupric chlorid. 



Name the following salts : FeCl 2 , FeCl 3 , FeSO 4 , 

 Fe 2 (S0 4 ) 3 , Fe(N0 3 ) 2 , Fe(NO 3 ) 3 , Fe(OH) 2 , Fe(OH) 3 , 

 HgCl, HgCl 2 , SnCl 2 , SnCl 4 , MnCl 4 , MnCl 2 . 



Experiment 10. Neutralization and preparation of salts. 

 Obtain two burettes from the instructor for these experiments. 

 Measure out 5 cc. of concentrated HC1 and 95 cc. of water ; 

 after mixing, fill one of the burettes with this diluted HC1 (Fig. 

 38). Use your funnel for filling the burette, and then carefully 

 wash the funnel. Prepare a dilute solution of NH 4 OH, using 90 

 cc. of water and 10 cc. of the shelf NH 4 OH. After mixing, fill the 

 second burette with this preparation of diluted NH 4 OH. Before 

 using the solution in the burette, it should be lowered to the zero- 

 point by carefully opening the pinch-cock. Always allow the tip 



