1. Lesson 6: Aim and Objectives Aim: How can we describe and compare attractions between molecules? Objectives: 1.Recognize the difference between intramolecular bonds and intermolecular bonds. 2.Be able to describe and compare strengths of intermolecular bonds. 3.Be able to diagram intermolecular bonds. 4.Be able to state the relationship between intermolecular bond strength and boiling point.

2. Types of Intermolecular Bonds 1.Hydrogen bonds 2.Dipole-dipole interactions 3.Van der Waals forces (Dispersion forces)

3. Boiling Points: What story do they tell? Period (Compound) Boiling Point (°C) (approximate) 2 (H 2 O)100 3 (H 2 S)-60 4 (H 2 Se)-41 5 (H 2 Te)-2 Period (Compound) Boiling Point (°C) (approximate) 2 (HF)20 3 (HCl)-85 4 (HBr)-66 5 (HI)-35 Period (Compound) Boiling Point (°C) (approximate) 2 (NH 3 )-33 3 (PH 3 )-88 4 (AsH 3 )-63 5 (SbH 3 )-17 Period (Compound) Boiling Point (°C) (approximate) 2 (CH 4 )-162 3 (SiH 4 )-112 4 (GeH 4 )-88 5 (SnH 4 )-52

5. Explain the Graphs Explain the graphs: – What is happening in Group 14? As ___________ increases, _________ _________. – What is happening in Groups 15-17?

6. Boiling Points of Hydrocarbons For hydrocarbons, as ____________________ increases, ________________ ______________.

7. Homework Pg. 112-115, Q 45-50, 36-38 Quiz Thursday: Bonding