SOME CHEMISTRY OF EVERYDAY LIFE 191 



sake of simplicity are represented as occurring in a series 

 thus: 



(1) NH 3 + H 2 O = NH 4 OH 



(2) C0 2 + H 2 = H 2 C0 3 



(3) NH 4 OH + H 2 CO 3 = H 2 O + H(NH 4 )CO 3 , or ammo- 

 nium bicarbonate 



(4) H(NH 4 )CO 3 + NaCl = NH 4 C1, or ammonium chlo- 

 ride, which remains in solution + HNaCO 3 , or sodium bicar- 

 bonate, which is precipitated. Hundreds of tons of salt are 

 worked up daily in making sodium bicarbonate at the Solvay 

 Works, Syracuse, N. Y. 



Upon heating the sodium bicarbonate sufficiently it is 

 converted into sodium carbonate (Na 2 CO 3 ), the well-known 

 " washing soda," one of the most extensively used of alkalies 

 in the arts and industries. The nature of the chemical 

 change that occurs is shown in the equation 



2 HNaCO 3 = H 2 O + CO 2 + Na 2 CO 3 . 



Enormous quantities of sodium carbonate are used in glass- 

 making, in soap-making, for washing powders, and in the 

 manufacture of the important compound known as "caustic 

 soda" or sodium hydroxide (NaOH). The wide range of 

 uses of sodium carbonate is due chiefly to the fact that it is 

 a cheap and effective agent to neutralize acids. 



It is to be noted in this connection, too, that sulphuric 

 acid occupies the same first rank in industrial importance 

 among acids that sodium carbonate does among alkalies. 

 The amazing total amount of this acid 1 used in the United 

 States, England, and Germany is expressive of the manu- 

 facturing and commercial enterprise of these nations. 



A description of the making of lime from the rock known 



1 According to the U. S. Census Report (1914) one hundred ninety-four 

 establishments reported the manufacture of over four million tons of sulphuric 

 acid. 



