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quantity of washing soda, and shake the tube. Then add 

 a drop or two of liquid soap to this mixture. Do suds 

 form ? Does a precipitate form ? What effect has wash- 

 ing soda on hard water ? 



EXPERIMENT 64. BAKING SODA 



(a) Mix a little baking soda with some vinegar and de- 

 scribe what occurs. Taste the mixture and describe it by 

 a single word. 



(b) Repeat (a) for buttermilk and sour milk. 



(c) Dissolve some cream of tartar in warm water, and 

 then by means of litmus paper determine whether it is an 

 acid or an alkali. Dissolve some baking soda in warm water 

 and mix it with the cream of tartar solution. Describe the 

 result. 



Mix dry cream of tartar and baking soda, and describe the 

 result. Pour hot water on the dry mixture and state what 

 happens. 



What is a mixture of dry baking soda and cream of tar- 

 tar called ? 



Why should soda not be used alone in baking? 



Why should it always be used in connection with an 

 acid ? 



EXPERIMENT 65. BAKING SODA 



Put some baking soda into a test tube and heat it over a 

 Bunsen flame. Let the gas which is formed bubble into 

 the limewater as in Figure 21. What is the effect on the 

 limewater ? What do you think the gas is ? 



After the baking soda has been heated for some time, 

 allow it to cool. Does it look different after the heating ? 



