2.6 Hydrogen Bonding

1. 2.6 Hydrogen Bonding 2.6.1. Hydrogen Bonds LO: I understand what is meant by hydrogen bonding.

2. The bonding in hydrogen fluoride is much stronger than can be accounted for by attractions alone. polar-polar This is bonding. hydrogen Increasing strength of bonds/forces van der Waals ionic hydrogen polar-polar covalent LO: I understand what is meant by hydrogen bonding.

3. + - H F + - H O + - H N Hydrogen bonds form in molecules where a hydrogen atom is bonded to a , or .atom. nitrogen oxygen fluorine H2O, CH3OH (methanol) NH3, CH3NH2 (methylamine) hydrogen Hydrogen bonds form between a atom in one molecule and a nitrogen, oxygen or fluorine atom in a neighbouring molecule. LO: I understand what is meant by hydrogen bonding.

4. 2.6.2. Boiling Points LO: I understand the pattern in the boiling points of the group 7 hydrides.

5. HF Boiling Point (˚C) Period number HI HBr HCl Boiling points of the group 7 hydrides vs period number. Extrapolating the graph from HCl downwards would give a boiling point of ˚C for HF. -100 Hydrogen bonding has increased the boiling point of HF by over 100˚C. LO: I understand the pattern in the boiling points of the group 7 hydrides.

6. 2.6.3. H-Bonds and Viscosity LO: I understand the affect H-bonds have on viscosity. LO: I understand the affect H-bonds have on viscosity.

7. propan-2-ol propanone Propan-2-ol is viscous than propanone due to the H-bonds between the molecules. H-bonds present H-bonds not present more The H-bonds between the propan-2-ol molecules prevent them from each other easily. slipping past LO: I understand the affect H-bonds have on viscosity.