You will need
  • * 0.5 l of water;
  • * wide non-metal bowl;
  • * 2 tablets gidroperita;
  • * crystals of potassium permanganate;
  • * potassium (sodium) nitrate;
  • * spoon for heating.
Instruction
1
The most affordable way is: put a bowl of water on the table and dissolve it in tablets gidroperita. To accelerate the process in advance they can be crushed.
2
Once gidroperit is completely dissolved, throw a few crystals of potassium permanganate, and stir. The liquid will hiss and begin to foam, these phenomena are accompanied by the secretion of oxygen.
3
Termination of hiss, accordingly, will mean the end of the reaction. To resume you have to add one component: the fluid is brown, add the peroxide, and if the color upon termination of the hiss has not changed - a couple of crystals of potassium permanganate.
Over a bowl, you can get some or just put her in her room and enjoy the easier breathing.
4
In order to get oxygen, you can also take potassium (sodium) nitrate (sold in shops for gardeners) and heat it in a spoon. In this case, the oxygen will be allocated in the heating process.