PRELIMINARY EXPERIMENTS 



13 



3. CARBON DIOXIDE 



Object. To learn some characteristic properties of car- 

 bon dioxide. 



Apparatus. A flask fitted up as in Figure 2, some broken marble, 

 two wide -mouth bottles, a little hydrochloric acid, and the appa- 

 ratus used in Experiment 2. 



Method. Place the broken marble in the flask, close 

 it with the rubber stopper, and add the hydrochloric acid. 

 Note the result. Col- 

 lect some of the gas in 

 a wide-mouth bottle 

 and test it with lime- 

 water. Result? Plunge 

 a burning stick into the 

 bottle of carbon di- 

 oxide. Result ? Select 

 two wide-mouth bottles 

 of equal size. Test 

 each with limewater. 

 Fill one jar with carbon 

 dioxide and leave the 



-Thistle Tube 



____ Delivery Tube 

 ..-..Stopper 



.Hydrochloric Acid 

 .marble 



FIG. 2. Preparing carbon dioxide. 



other full of air. Now 



invert the jar full of carbon dioxide over the other. After 

 a few moments test the contents of each bottle. Which 

 one now contains the carbon dioxide? 



What does this show as to the weight of this substance 

 as compared with the air ? 



Let carbon dioxide bubble through a test tube of pure 

 water for a few minutes. Taste of the water. .What pecul- 

 iarity has the taste? 



Conclusion. State briefly what you have learned about 



