Boiling point of water is
<p>101<sup>0</sup></p>
<p>0<sup>0</sup></p>
<p>100<sup>0</sup></p>
<p>-100<sup>0</sup></p>
When water freezes to solid, its volume
decreases
Increases
Constant
None of these
Causes of permanent hardness of water.
Calcium Oxide
Magnesium Sulphate
Calcium Sulphate
Mangnesium Oxide
40
<p>5<sup>0</sup></p>
<p>3<sup>0</sup></p>
The temperature at which ice melt is
melting point
heating point
boiling point
freezing point
The presence of high coliform counts in water indicate
Contamination by human wastes
Phosphorus contamination
Decreased biological oxygen demand
Hydrocarbon contamination
Human body has about .............of water by weight
90%
70%
50%
65%
Cause of temporary hardness of water
Calcium Carbonate
Calcium bicarbonate
Sodium carbonate
Water is also called.................
a chemical
an universal solvent
vapour
solution
