144 EXPERIMENTAL GENERAL SCIENCE 



11. If alcohol and water were mixed together, which would be driven 

 off first when heat was applied? 



12. Sea water is unfit to drink because of various salts dissolved in 

 it. Can you suggest a method of obtaining pure water from sea water? 



13. Put about a spoonful of powdered soft coal into a test-tube, cork 

 with a one-hole stopper containing a glass tube. Apply heat from the 

 bunsen burner. What is given off through the glass tube? 



14. Will this substance burn? 



16. What form of distillation is illustrated by the preceding experiment ? 



16. Turpentine is obtained from the pitch of various pine trees which 

 is heated with water. The volatile turpentine is driven off and resin or 

 rosin is left. What phase of distillation does this illustrate? 



17. In many chemical experiments, it is necessary to use distilled 

 water. Why not use ordinary water? 



