The Chemistry of Titanium 1e – Bonding and Properties
Learning Intentions To relate Melting and Boiling Point, Electrical Conductivity, Viscosity and Solubility to the structure and bonding of substances To use information on substances to identify the bonding present
Melting and Boiling Points SubstanceBond brokenMelting/boiling point MetalMetallicHigh Ionic LatticeIonic bondHigh Covalent NetworkCovalent bondHigh Covalent MoleculeVan der Waals forcesLow
General Rule: The stronger the bond or force that needs to be broken to get the substance to melt or boil, the higher its melting or boiling point
Viscosity of Liquids The stronger the force of attraction between molecules the greater the viscosity or thickness of the liquid
Electrical Conductivity in Metals
Electrical Conductivity in Ionic Liquids
General rule for Electrical Conductivity In order for something to conduct it must contain charged particles (electrons or ions) that are free to move
Solubility General Rule: As a rule of thumb, in terms of solubility, “like dissolves like” Ionic substances dissolve in polar solvents eg ammonium chloride in water` Non-polar dissolve in non-polar solvents eg wax in paraffin / nail polish in acetone
Polar Molecules Water is a polar molecule so it is a polar solvent. A liquid that substances dissolves in is called a SOLVENT. Solvents can be either polar or non-polar molecules. Immiscible liquids do not mix, e.g. oil and water, however, non-polar liquids are miscible with each other. Polar solvents will usually dissolve polar molecules. Non-polar solvents will usually dissolve non-polar molecules. ++ ++ --
Dissolving in Water Generally, covalent molecules are insoluble in water. However, small molecules like ethanol (C 2 H 5 OH), with a polar O-H functional group, will dissolve, Hydrated ions Ionic Compound dissolving in water -- ++ ++ H2OH2O -- ++ ++ -- ++ + -- ++ ++ -- ++ ++ -- ++ ++ ++ -- ++ ++ + -- ++ -- ++ ++ Ethanol ++ O H HH H H CC H --
Dissolving in a non-polar solvent