CHAPTER XIV 

 NEUTRALIZATION 



The " Neutralization " of Cream 



Neutralization. The principle of neutralization is not a new 

 one. Its application in the laboratory is practically as old as 

 the science of chemistry, but its application to cream is compara- 

 tively recent. 



The principle is easily explained and understood. In chem- 

 istry there are two large classes of substances which are opposite 

 to each other in action and have a strong affinity for each other, 

 namely, bases (which include alkalies) and acids. A base and 

 an acid, when brought together, react upon each other to form a 

 new substance which is neither an acid nor an alkali, and is 

 called a salt. For example, when hydrochloric acid and caustic 

 soda react upon each other common salt and water are formed, 

 thus, 



HC1 + NaOH = NaCl + H 2 O 



(Hydrochloric Acid) (Caustic Soda) (Common salt) (Water) 



Again, when either quicklime or slaked lime (hydrate of lime) 

 reacts with hydrochloric acid they form calcium chloride, which 

 is the salt commonly used for making the brine used in connec- 

 tion with refrigerator systems, as it can be reduced to a very low 

 temperature without freezing. 



CaO + 2HC1 = CaCl 2 + H 2 O 



(Quicklime) (Calcium chloride) 



or 



Ca(OH) 2 + 2HC1 - Cad? + 2 H 2 O 



(Slaked lime) 



183 



