Oxygen is put in cylinders for use where natural supply is not sufficiently enough.
This is mainly in:
(i) Mountain climbing/Mountaineering-at high altitudes, the concentration of air/oxygen is low.
Mountain climbers must therefore carry their own supply of oxygen for breathing.
(ii) Deep sea diving-Deep sea divers carry their own supply of Oxygen.
(iii) Saving life in hospitals for patients with breathing problems and during anaethesia.
A mixture of oxygen and some other gases produces a flame that is very hot.
(i) Oxy-acetyline/ethyne flame is produced when Ethyne/acetylene gas is burnt in pure oxygen.
The flame has a temperature of about 3000oC.It is used for welding/cuttingmetals.
(ii)Oxy-hydrogen flame is produced when Hydrogen is burn in pure oxygen. The flame has a temperature of about 2000oC.It is used also for welding/cuttingmetals.
- Oxy-hydrogen mixture is used as rocket fuel
- A mixture of charcoal, petrol and liquid Oxygen is an explosive.
(d) Chemical properties of Oxygen /combustion.
Oxygen is a very reactive non-metal. Many elements react with oxygen through burning to form a group of compounds called Oxides. Burning/combustion is the reaction of Oxygen with an element/substances. Reaction in which a substance is added oxygen is called Oxidation reaction. Burning/combustion is an example of an oxidation reaction.
Most non-metals burn in Oxygen/air to form an Oxide which in solution / dissolved in water is acidic in nature. They turn blue litmus red. e.g. Carbon(IV)oxide/CO2 ,Nitrogen(IV)oxide/NO2 ,Sulphur(IV)oxide/SO2. Some non-metals burns in Oxygen/air to form an Oxide which in solution / dissolved in water is neutral in nature. They don’t turn blue or red litmus. e.g. Carbon(II)oxide/CO, Water/H2 O.
All metals burns in Oxygen/air to form an Oxide which in solution/dissolved in water is basic/alkaline in nature. They turn red litmus blue. e.g. Magnesium oxide/MgO, Sodium Oxide/ Na2 O. Copper(II)oxide/CuO Elements/substances burn faster in pure Oxygen than in air. Air contains the inactive part of air that slows the rate of burning of substances/elements.