hydrates
Covalent Network Solids
Formed from elements in the Carbon group due to their ability to make 4 covalent bonds.
Examples:
Silicon: Semiconductor, forms 3-D networks similar to carbon.
SiO2 (Quartz).
Hydrates: Guided Notes
Solid crystals containing water.
Vocabulary
Hydrated: Contains water in its structure.
Anhydrous: Salt compound of a hydrate without water attached.
Hydrophilic: Water-loving; can mix and interact with water.
Hydrophobic: Molecules that do not mix with water.
Desiccant: A substance that absorbs water controlling moisture.
Introduction to Hydrates
Chemical compounds that contain water in their crystal structure, essential for the chemical formula.
Specific number of water molecules associated with each formula unit.
Naming Practice
Examples of Compounds:
Lithium chloride tetrahydrate: LiCl·4H₂O
Magnesium sulfate heptahydrate: MgSO4·7H₂O
Barium hydroxide octahydrate: Ba(OH)₂·8H₂O
Sodium carbonate decahydrate: Na₂CO₃·10H₂O
Anhydride/Anhydrous:
(Noun) The light blue powder is the anhydride.
(Adjective) Anhydrous copper (II) sulfate left after heating.
Types of Hydrates
Efflorescent Hydrates:
Weakly bonded water, easily lost, high vapor pressure, can become anhydrous in low ambient air pressure.
Hygroscopic Hydrates:
Strongly bonded water, easily gains moisture, low vapor pressure, often used as desiccants.
Deliquescent Hydrates:
Hygroscopic substances that absorb enough moisture to dissolve and form a liquid solution.