I 4 GENERAL SCIENCE 



compounds, called bases, which will neutralize the acids 

 and prevent their destructive action. 



12. Bases. Bases, or alkalies, are substances or 

 compounds such as household ammonia (NH 4 OH); 

 potash lye (KOH), which is also called caustic potash; 

 soda lye, or caustic soda (NaOH); and slaked lime 

 (CaO2H 2 ), which is used for building purposes. 



In the home the bases are more commonly used than 

 the acids. They are used largely for cleansing purposes, 

 and potash lye is used for making soap. The lye, 

 properly diluted, is very valuable for removing grease 

 from drain pipes and sinks. Household ammonia is 

 ammonia in diluted form, and a small amount in water 

 is very useful for house cleaning, and also for washing deli- 

 cate fabrics and for the removal of stains and grease spots. 



The strong bases, like the acids, must be used with 

 considerable care and caution. If they come in contact 

 with the hands or clothing, they have a caustic or "eating" 

 effect and usually will discolor the clothing. If a base is 

 spilled, it can be neutralized by pouring on it at once 

 some dilute acid. The best acids to use for this purpose 

 are hydrochloric and acetic acids. In the home, lemon 

 juice or vinegar would do. If any acid is spilled, it can 

 be neutralized by pouring on it at once a base. Am- 

 monia is the best, as it is the least harmful if too much 

 of it should be used. The strong acids and bases act 

 very quickly on the body and clothing, and in case of 

 accident the neutralizer must be used without delay or 

 the harmful work will be done and there will be no remedy. 

 A base will neutralize an acid and an acid will neutralize 

 a base. Limewater, a mild base, is sometimes prescribed 

 by physicians to neutralize the acids in the stomach and 

 thus aid digestion. 



