Kintetic Molecular Theory Phases of Matter Kintetic Molecular Theory

Phases of Matter Mr Kent’s Chemistry Page Phases of Matter Animation

Phases of Matter WebVision Animation Particle Motion in Phases of Matter

Phases of Matter WebVision Animation Particle Motion in Phases of Matter

Phases of Matter Sodium Acetate Crystals

Types of Intermolecular Forces The boiling point and the melting point of a substance depend on the strength of the intermolecular forces. The stronger the attractive force the higher the boiling point and the melting point temperature.

Dispersion Forces (Van der Waals Forces) - the attraction between molecules caused by oppositely charged ends of the compound (a temporary condition – temporary dipole). Draw example diagram an attractive force that exists between all molecules. the strength of the dispersion force increases with increasing atomic size, increasing mass and decreasing distance between molecules. The melting and boiling points increase with increasing atomic size & mass.

Dipole-Dipole Forces attractions between opposite charges of neighboring permanent dipoles (polar molecules) Draw example diagram

Hydrogen Bonding occurs between molecules of any compound in which hydrogen is bonded to fluorine, oxygen, or nitrogen. These are the three most electronegative nonmetals, (F – 4.0, O – 3.4, N – 3.0) and have the strongest attraction for electrons and hydrogen has a much lower electronegativity (H- 2.2) creating a large difference in pull for the electrons and large partial charges on the atoms of these molecules.

The large partial charges result in extremely strong dipole-dipole force. Hydrogen bonds are stronger than dispersion or dipole-dipole forces. Molecules with hydrogen bonds have higher boiling and melting points.

Water Dihydrogen sulfide H2O has a higher boiling point than H2S because of hydrogen bonding. BPH2O = 100 ºC

Surface Tension - the imbalance of forces at the surface of a liquid. The stronger the intermolecular forces of attraction, the greater the surface tension.

Some Unique Properties of Water: high boiling point _____________ high specific heat _____________ density of solid state of water (ice) is less than density of liquid state (0.9150 g/ml) (0.9999 g/ml) high surface tension high heat of vaporization excellent solvent because of polar nature of molecule Use your notes and Read p 385-389 in textbook to complete worksheets: 13-1 and 13-2 Review & Reinforcement

Some Unique Properties of Water: high boiling point 100 °C high specific heat density of solid state of water (ice) is less than density of liquid state (0.9150 g/ml) (0.9999 g/ml) high surface tension high heat of vaporization excellent solvent because of polar nature of molecule Use your notes and Read p 385-389 in textbook to complete worksheets: 13-1 and 13-2 Review & Reinforcement

Some Unique Properties of Water: high boiling point 100 °C high specific heat 4.18 J/g °C density of solid state of water (ice) is less than density of liquid state (0.9150 g/ml) (0.9999 g/ml) high surface tension high heat of vaporization excellent solvent because of polar nature of molecule

Some Unique Properties of Water: high boiling point 100 °C high specific heat 4.18 J/g °C density of solid state of water (ice) is less than density of liquid state (0.9150 g/ml) (0.9999 g/ml) high surface tension high heat of vaporization excellent solvent because of polar nature of molecule Use your notes and Read p 385-389 in textbook to complete worksheets: 13-1 and 13-2 Review & Reinforcement