How much Oxygen is in the air?
-A wide mouthed jar
-Water to fill the dish halfway up
-Food coloring for the water (optional)
- Be careful not to spill water on
- Be careful not to burn yourself or others with the matches and candle.
1. Light candle, set candle on melted drippings in the center of the dish
2. Fill pan half full of water.
3. Turn jar over and place it over the candle.
4. Observe results
1. What are the components of air?
2. Why does the candle go out?
3. Why does the water rise in the jar?
The candle needs oxygen to burn. When the jar is placed over the candle
the amount of oxygen available becomes limited and the candle consumes all of it.
The candle flame has removed most of the oxygen from the air in the jar. The
pressure of the air left inside the jar has been reduced below that of the air outside.
The water rises in the jar approximately one fifth of the way up. Therefore
we assume that air is made of approximately 1/5 oxygen.