Advertisements
Advertisements
प्रश्न
Describe a simple experiment to show that l/5th of air is oxygen.
Advertisements
उत्तर
Aim : To show that l/5th of the air is oxygen.
apparatus required : Glass trough, bell jar, stopper, water, phos-phorus, evaporating dish
PROCEDURE
- a glass trough is filled with water
- A dry evaporating dish containing white phosphorus is made to float on the water.
- This apparatus is covered with a well stoppered bell jar with markings on its side.
- A glowing iron wire is introduced into the bell jar by opening the stopper
- The phosphorus is carefully ignited.
- Re-stopper the apparatus
- The phosphorus bums with a brilliant flame farming dense white fumes of phosphorus pentoxide.
- Soon the burning ceases and the water level starts rising.
- The water occupies approximately l/5th of the original volume, as the fumes dissolve in water.
- Some phosphorus is left unburnt in the dish. The air left behind in the bell jar does not allow the phosphorus to burn.
INFERENCE : The experiment shows that the volume of air oc-cupied by oxygen is 1 /5th.

APPEARS IN
संबंधित प्रश्न
Statement given below is incorrect. Write the correct statement :
Symbiotic bacteria are present in nodules of cereal plants such as wheat.
Briefly state the importance of Oxygen.
Write fully balanced equation for the following :
CO2 + H2O →
Give the chemical name of rust.
State a reason why there is a balance in the amount of carbon dioxide in the air, even though carbon dioxide is released into the atmopshere by various processes.
Name the following:
A process which removes carbon dioxide from the air.
Match the following.
| Nitrogen | Respiration in living animals |
| Oxygen | Fertilizer |
| Carbon dioxide | Refrigerator |
| Dry ice | Fire extinguisher |
How will you prove that air supports burning?
When cooled to -57°C, gaseous carbon-di-oxide becomes a liquid.
Explain the following observations very briefly
Breathing through mouth may harm you.
