Properties of Water


States of Water

  • Liquid - water
  • Solid - ice
  • Gas - steam


Hard and Soft Water

Hardness of water is due to the presence of calcium and magnesium salts.


Hard water may be divided into two classes:

  • Permanently hard water containing sulphates of lime
  • Temporarily hard water containing carbonates of lime.


Water may contain

  • Hydrogen Sulphide - causing odor
  • Iron and Magnesium - causing rust or stain on fixtures
  • Turbidity - particles in suspension causing cloudiness
  • Bacteria - pathogens. protozoa, viruses, amoeba
  • chemicals and petroleum products.


Density of Water

Density is the ratio of mass to volume. It is determined by the closeness of particles of a substance.


Specific Gravity

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MERCURY


Unit Volume

1 cubic inch

weights 0.488 lbs.

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WATER


Unit Volume

1 cubic inch

weights 0.036 lbs.


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Materials which have a S. G. greater than 1 will sink in water.

Materials which have a S. G. less than 1 will float in water.


Behavior of Water


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  • Boiling Point of Water           = 100oC or 212oF
  • Freezing Point of Water        = 0oC or 32oF
  • Maximum Density of Water   = 4oC or 39.2oF


  • Water expands in volume by approximately 1700 times when it changes state to steam.


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  • Water expands in volume by approximately 1 1/10 times (110 %) when it changes state to ice.


Effect of Pressure on Water

  • Under 0 P. S. I. G. or 14.7 P. S. I. A. (sea level) water boils at 100o C or 212o F.
  • As pressure increases, the boiling point increases.
  • If pressure decreases, the boiling point decreases.
  • In vacuum water boils at 60o F.


Weights and Measures of Water

  • 1 cubic foot of water        = 62.5 pounds
  • 1 gallon of water (Imperial) = 10 pounds
  • 1 cubic foot of water        = 6.25 gallons
  • 1 Imperial gallon               = 160 ounces
  • 1 American gallon            = 128 ounces


Conversion

  • Imperial gallon x 5/6   =   American gallon (approximately)
  • American gallon x 6/5 =  Imperial gallon (approximately)


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