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Oxygen
preparation, detection,
reactions

Aids and
chemicals:
 | for O2 preparation: gas
evolver (test tube with side hole and separator tube), stand, clamp,
holder, beaker (100 cm3), test tube holder and stand, H2O2
solution (w =
10%), burel tablets |
 | MnO2 - catalysator (prepared of 2
cement portion, 1 burel portion and water, the leave to dry in plastic
coat), plumbum Pb, ethanol C2H5OH, chip,
cigarette, burner |
 | simple gas evolver: film coat, stopper punched
by 2 hypodermic needles (1,2 x 40 mm), 10 cm3 hypodermic
syringe, 20 cm3 hypodermic
syringe (with rubber plunger coated with
silicone oil), beaker (for H2O2), paper |
Working process:
Detection of O2
Burning cigarette with hypodermic needle
which is put to syringe with O2 from cigarette filter to
burning part and slowly extrude, the cigarette starts intensively
burning. |

Reaction of O2
with H2
Fill the syringe with 6 cm3
of O2. From other simple gas evolver fill it
with 12 cm3
of H2. Put this explosive gas into soap
solution and burn bubles. |
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Observation
 | O2 is evolved in catalytical
decomposition of H2O2, and O2
supports burning. |

Vysvetlenie
 | 2 H2O2
---------> 2 H2O + O2 |

Remarks
 | Use high grade powdered burel in
preparation of catalysator tablets . |
 | As founding forms use various plastic
coats. |

Exhalate
annihilation
 | No dangerous substance is evolved in these
experiments. |
 | Cleaning the apparature is very simple. |

Safety
 | 10% solution of H2O2 dip
the skin, prevent the skin from direct contact with H2O2. |
 | Prevent the simple gas evolver from over
pressure. |
 | Do not breathe powdered burel! |
 | Use protection shield! |
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