EXERCISE 32 

 WHAT IS THE COMPOSITION OF CARBON DIOXIDE? 



Materials. Bottle ; oxygen generator ; charcoal ; forceps ; limewater. 



Directions. Fill a bottle with oxygen. Heat a piece of charcoal (carbon) in a flame, holding it 

 with a forceps, until it is red-hot, and then thrust it into the bottle of oxygen. Observe what happens. 

 Hold it in the bottle until it no longer glows and then remove it. Test the gas in the bottle by 

 lowering a flaming match into it. What do you think it is ? Now add about 10 cubic centimeters 

 of limewater and shake the bottle. What does the result prove the gas to be? What does this 

 prove about the composition of the gas given off. by a candle ? Where do the carbon and the oxygen 

 come from ? 



Additional problems. If paraffin wax is composed of carbon and hydrogen only, how do you explain the 

 formation of carbon dioxide and water when the candle burns ? 



Why is the candle flame hottest in the thin blue layer on the outside of the flame ? 

 Why does not the gas burn in the inner cone of the flame ? 



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