44 



LABORATORY MANUAL 



Directions: Into a flask put about 200 c.c. of water 

 and 3 or 4 teaspoonfuls of salt. Stir or shake the mix- 

 ture until all the salt has dissolved. Then insert the 



delivery tube through 

 the stopper and close 

 the flask. Heat the 

 solution to boiling. Put 

 the free end of the tube 

 into a test tube which 

 is surrounded by cold 

 water. Keep the water 

 cold by adding ice or 

 snoAv. Boil the water 

 in the flask for about 

 5 minutes. Taste the 



^S^--C -^2*^ 



F[S - 16 - liquid that has distilled 



over into the test tube. Is there any salt present ? Of 

 what commercial value is distillation? 



Exercise 21. Evaporation. 



Object: To show a result of evaporation. 



Thermometer 

 Chloroform 



Apparatus 



Absorbent cotton 



Directions: Wrap a small bit of cotton tightly 

 about the bulb of a thermometer. Record the reading 

 of the thermometer. Saturate the cotton with chloro- 

 form and wave the thermometer in the air to evap- 

 orate the chloroform. -As it evaporates what change 



