1. Bonding
Intermolecular forces 1

2. Kinds of molecules 2

3. Proof for existence of intermolecular forces3

4. Types of Intermolecular forces4

5. Examples to explain Van der waals’ forces5

6. Examples to explain dipole-dipole forces6

7. Hydrogen bonding Hδ+— Fδ- ---------------Hδ+— Fδ- hydrogen bond
Considerably stronger than other intermolecular forces.
Affects the physical properties of the compounds in which it exists. 7

8. Examples of H-Bonding 8

9. Hydrogen Bonding in diff. compounds9

10. Examples of H-Bonding contd….10

11. Examples of H-Bonding contd….11

12. Trends in Boiling points of Groups 4,5,6 and 712

13. Examples of H-Bonding contd….13

14. Anomalous behavior of Water14

15. Structure of ICE 15

16. Hydrogen Bonds in Water, Ice16

17. Compare H2O and H2S Properties Water Hydrogen sulphide
Molar enthalpy of fusion
6.0 kJmol-1
2.4 kJmol-1
Molar enthalpy of vaporization
41.0 kJmol-1
19.0 kJmol-1
State at room temperature & Pressure
Liquid
Gas
Electro negativity
Very high
Less
Size
O atom is small
S is larger than O
Hydrogen Bonding
2 H bonds per molecule of water
No H Bonding 17

18. Effect of H bonding on Organic compounds- case 118

19. Dimer of Ethanoic acid 19

20. Effect of H bonding on Organic compounds- case 2
Propanone is miscible in water but it has no H bonding between propanone molecules
This is because its O atoms can bond to water molecules. 20

21. Effect of H bonding on Organic compounds- case 3
p- nitro phenol or 4- nitro phenol is having intermolecular H bonds , stronger forces of interaction between molecules and so its BP is 279°C
o- nitro phenol or 2- nitro phenol has intramolecular H bonds, weaker forces of interaction between molecules and so has lower BP of 216°C 21

22. Biological importance of H bonding
DNA pairing occurs due to H bonds.
Secondary structure of proteins (α helix and β pleated proteins)
α helix-is an example of INTRA MOLECULAR H Bonding 22

23. Hydrogen bonds in DNA Base Pairs
2 H bonds between Adenine and Thymine
3 H bonds between Cytosine and Guanine 23