Achiever's Dream Chemical Bonding Pt 2 Notes

The Chemistry Specialist Chemical Bonding Part 2

© Achievers Dream Structure Bonding Factors affecting strength of bonds / IMF Properties Chemical Bonding Giant metallic lattice structure e.g. Na, Mg, Al Giant ionic lattice structure e.g. NaCl, MgO Giant molecular structure e.g. Diamond, Graphite, Silicon, Silicon dioxide Simple molecular structure e.g. H 2, O2, H2O, CO2, Ne (monoatomic element) (Strong) Electrostatic forces of attraction / metallic bond between cations and sea of delocalised mobile electrons Strength of Metallic Bond (Strong) Electrostatic forces of attraction / ionic bond between two oppositely charged ions. (Strong) Covalent bond between atoms (Weak) Intermolecular forces of attraction between molecules id - id - non polar More electrons to be polarised Stronger id - id Linear Molecules Stronger id - id Larger Surface area of contact between molecules pd - d - polar hydrogen bonding - polar 1. Charge Density No. of valence electrons contributed by each atom (strength q₊) 2. q₊ r₊ Strength of Ionic Bond 1. Bond Order Size of Electron Cloud Shape (Isomers) Magnitude of dipole moment Extent of H-bonding *Compare charges first before ionic radii q₊ x q₋ r₊ + r₋|L.E.| 2. Bond Length 3. Bond Polarity (Greater Difference in High m.p. and b.p. (large amount of energy required to overcome the metallic bonds) Good conductor of electricity (solid and molten) Good conductor of heat High m.p. and b.p. (large amount of energy required to overcome the ionic bonds) Good conductor of electricity (molten and aqueous) Soluble in polar solvent Low m.p. and b.p. Non-polar molecules are soluble in non-polar solvent while polar molecules are soluble in polar Non-conductor of electricity High m.p. and b.p. (large amount of energy required to break the covalent bonds) T etrahedral arrangement Cannot conduct electricity Diamond and SiO 2 T etrahedral arrangement Semi-conductor Silicon Layered structure of hexagonal rings Weak id-id forces between layers planes Graphite (Higher Stronger) (Shorter Stronger) Average no. of H-bond per molecule bond polarity H - N < H - O < H - F