Page 79 - CITS - Welder - Trade Theory

WELDER - CITS

Fig 2

Oxygen - properties - manufacturing method

Objectives : At the end of this lesson you shall be able to
• explain the oxygen properties.
• explain the oxygen manufacturing method.

Introduction
Properties of oxygen gas:
1 Oxygen is a supporter of combustion. Its chemical symbol is O2
2 Oxygen is colourless, odorless and tasteless gas,
3 It has atomic weight of 16.
4 Its specific gravity at 32° F and at normal atmosphere pressure is 1.1053, as compared with air. It is slightly
soluble in water.
5 it does not burn itself, but readily supports combustion fuels
When compressed oxygen comes in contact with finely divided particles of combustible material (i.e., coal dust,
mineral oil, grease) it will self-ignite them, leading to fire or explosion. Self-ignition in such cases may be initiated
by the heat given up suddenly by compressed oxygen, oxygen becomes liquefied at a temperature of -182.962°C
at normal atmospheric pressure. Liquid oxygen has a pale blue colour. liquid oxygen becomes solid at - 218.4 C°
at normal atmospheric pressure. It combines rapidly with most of the metals and forms oxide. i.e..
Iron + oxygen = Iron oxide
Copper + oxygen = Cuprous oxide
Aluminium + oxygen = Aluminium oxide

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CITS : C G & M - Welder - Lesson 14-26 CITS : C G & M - Welder - Lesson 14-26