When water freezes to solid, its volume
decreases
Increases
Constant
None of these
Human body has about .............of water by weight
90%
70%
50%
65%
Water is also called.................
a chemical
an universal solvent
vapour
solution
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>
One water molecule consists of two.............atom and one..............atom.
Hydrogen, Oxygen
Chlorine, Oxygen
Hydrogen, sodium
sodium, chlorine
40
<p>5<sup>0</sup></p>
<p>3<sup>0</sup></p>
Causes of permanent hardness of water.
Calcium Oxide
Magnesium Sulphate
Calcium Sulphate
Mangnesium Oxide
Cause of temporary hardness of water
Calcium Carbonate
Calcium bicarbonate
Sodium carbonate
The presence of high coliform counts in water indicate
Contamination by human wastes
Phosphorus contamination
Decreased biological oxygen demand
Hydrocarbon contamination
