1. WATER IN CHEMISTRY
Water- H20 It consists of two hydrogen atoms and one oxygen atom. Molecular weight of two hydrogen
atoms is 2u, 16u of oxygen.
The molecular weight of water is 18U. Location on the periodic table. Hydrogen is the first main group, in
the first period. Oxygen is in the 16th group (6th main group), in 2nd period.
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Temperatures:
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At 4 degrees Celsius oxygen is dissolved in water.
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Water freezes at 0 degrees Celsius and boils at 100 degrees Celsius.
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Water exists in three states of matter.
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Liquid (water)
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Gaseous (water vapor)
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Solid state (ice)
3. Several types of water:
- Hydrogen peroxide - 3% aqueous hydrogen peroxide solution used to disinfection
- Distilled water - Purified water not containing dissolved salts, used in laboratories and car batteries.
- Hard water - water containing dissolved compounds of magnesium and calcium.