A YEAR IN SCIENCE 



25 



Gas generator 

 Lime water 



Exercise 6. Diffusion of Gases. 



Object: Will gases diffuse when in contact? 



Apparatus 



Wide mouth bottles 

 Glass covers 



Directions: From a gas generator fill a bottle with 

 carbon dioxide.* Carbon dioxide is heavier than air 

 and so displaces the air which was in the bottle. Pour 

 lime water into the bottle. By shak- 

 ing the bottle thoroughly, mix the 

 lime water with the carbon dioxide. 

 What change do you note in the lime 

 water ? Such a change in lime water 

 indicates the presence of carbon 

 dioxide. From the generator fill 

 another bottle with carbon dioxide. 

 Cover the bottle with a glass plate 

 and remove it to your desk. Over 

 the mouth of this bottle invert a 

 bottle of air and then remove the 

 glass plate. Allow the bottles to 

 stand in this relation five minutes. 

 Remove the upper bottle and cover 

 it immediately with the glass plate, 

 carbon dioxide in the upper bottle? 

 determine this ? What does this show ? 



Is there any 

 How do you 



*To generate carbon dioxide, place a few small pieces of marble 

 in a flask and cover with dilute hydrochloric acid. The flask 

 should be fitted with a delivery tube through which the gas can 

 pass into the wide mouth bottle. 





