LABORATORY MANUAL 23 



EXERCISE XV (Textbook 155) 

 STUDY OF GAS BURNERS AND FLAMES 



Gas flames are of two kinds, luminous (light-giving) and 

 non-luminous. A laboratory burner is called a Bunsen 

 burner (from the name of the German chemist who invented 

 it). Use these terms whenever appropriate in this exercise. 



APPARATUS: A Bunsen burner, a porcelain evaporating 

 dish, a laboratory thermometer. 



DIRECTIONS FOR WORK: 



(1) Examine the Bunsen burner carefully and write a 

 brief description of it. Make a drawing of it on the first 

 page. 



(2) Adjust the brass ring at the base of the burner so that 

 the holes are covered. Turn on the gas full head, and then 

 bring a lighted match over the burner. Turn the stopcock 

 until the flame is about two inches long, and describe it. 



(3) Hold the outside of an evaporating dish in the upper 

 part of flame for a few seconds and describe any change in 

 the appearance of the dish. 



(4) Turn the brass ring at the base of burner until the 

 flame is entirely changed in appearance. Describe this 

 flame. 



(5) Hold a clean evaporating dish in the flame for a few 

 seconds and record observations. 



RESULTS 



1. What kind of flame has an ordinary gas burner? 



2. How can a similar flame be made with a Bunsen burner? 



3. What kind of flame has a gas stove or range? 



4. How can a similar flame be made with a Bunsen burner? 



5. Which is the cleaner of the two flames, the one in Case 

 2 or Case 4? 



6. Give a name for the coating formed on the evaporating 

 dish. 



