1. Take about 5-10 minutes to review/complete your worksheet from last class with your partner What worksheet? Introduction to Liquids and Solutions Also, remember your new seats from last class!

2. Intermolecular Forces London Dispersion Dipole- dipole Hydrogen Bonding Ionic Bonding All types of Covalent Bonds Weak Strong

3. London Dispersion Occurs between noble gases or nonpolar molecules (H 2, N 2, etc.) For an instant, the electrons are not evenly distributed around the atom/molecule London Dispersion Dipole- dipole Hydrogen Bonding Ionic Bonding

4. London Dispersion Because of the uneven distribution, temporary, instantaneous dipole is created Neighboring molecules can be affected and an induced dipole can occur London Dispersion Dipole- dipole Hydrogen Bonding Ionic Bonding

5. London Dispersion These forces are very weak and short-lived As the size of an atom/molecule increases, the LDF also increases In order for a substance that has LDF to freeze, the molecules must be moving extremely slow so freezing points are low (N 2 = -210˚C, 63 K) London Dispersion Dipole- dipole Hydrogen Bonding Ionic Bonding

6. Dipole-Dipole Force of attraction between two polar molecules The dipole in each molecule is not temporary/instantaneous These are about 1/100 of the strength of covalent bonds London Dispersion Dipole- dipole Hydrogen Bonding Ionic Bonding

7. Hydrogen Bonding This is a form of dipole-dipole interaction Occurs when a hydrogen atom (small) is bonded to N, O, or F (highly electronegative) Electronegativity can affect strength (O>N) About 4x stronger than dipole-dipole London Dispersion Dipole- dipole Hydrogen Bonding Ionic Bonding

8. Ionic, Molecular, Atomic Solids Ionic (NaCl) – between ions – repeating pattern, packed together – High melting point Molecular (Ice) – Fundamental particle is molecule, but has many of these molecules – Low melting point Atomic (Diamond) – Covalent bonds between the same atom over and over – One huge molecule, NOT a collection of many small ones

9. Metallic Bonds

10. _ _ _ _ _ _ _ _ _ __ _ _ + Aluminum-13 13 p+ Now only 10 e- Cation! +

11. + ++++++++++++ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ Conductors!

12. + + + + + + + + + + + + + + + + + + + + _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ Malleable! Ductile!

13. Ionic Compounds are not malleable/ductile… _ _ + _ _ + + + + + + + + + _ _ _ _ _ _ + _ _ + + _ _ + + _ _ + + + + + __ _ _

14. Properties of Metallic bonds Varying melting points – Temperature at which substance changes from solid to liquid – Mercury vs. Tungsten

15. Alloys

16. Types of Alloys

17. Molarity Moles per liter Must convert grams to moles; mL to L Has to do with solubility – How much of a solute (solid) is dissolved in a solvent (liquid) – “like dissolves like” –polarities Terminology: saturated, unsaturated, supersaturated, dilute, concentrated

18. Dilutions Only water is added to a stock solution to dilute something The amount of SOLUTE before the dilution is the same as the amount of solute after the dilution Will stay the same Will increase

19. Dilutions M 1 x V 1 = moles of solute = M 2 x V 2 Or you can just use M 1 x V 1 = M 2 x V 2