1. Hydrogen bonding occurs between hydrogen atoms attached to electronegative atoms like oxygen, fluorine, and nitrogen of one molecule and an electronegative atom of another molecule. 2. Water is able to form extensive hydrogen bonding networks between molecules due to each water molecule having two hydrogen atoms and two lone pairs of electrons on the oxygen atom. 3. The hydrogen bonding network in liquid water is responsible for its unique properties, while hydrogen bonding in ice forms its crystalline lattice structure.

1. Hydrogen Bonding 8.4 Water (Prelim) 8.4.2 The wide distribution and importance of water on Earth is a consequence of its molecular structure and hydrogen bonding

2. Syllabus Points Stage 6 preliminary unit on Water. describe hydrogen bonding between molecules plan and perform an investigation to identify and describe the effect of anti-freeze or salt on the boiling point of water

3. Explanations..

4. What is a Hydrogen Bond? Hydrogen bonds are the attractive force between the hydrogen attached to an electronegative atom of one molecule and an electronegative atom of a different molecule. Hydrogen (H) needs to be attached to a highly electronegative Oxygen (O), Fluoride (F), Nitrogen (N) atom.

5. Why are O, F & N so attractive?? In each of these molecules note: 1. A hydrogen atom! 2. the hydrogen is attached directly to one of the most electronegative elements, causing the hydrogen to acquire a significant amount of positive charge. 3. Each of the elements to which the hydrogen is attached is not only significantly negative, but also has at least one "active" lone pair. In these interactions, a hydrogen atom is the donor, and the respective electronegative atom is the acceptor of the bond. Electronegativity Values F (4.0) O (3.5) N(3.0)

6. Hydrogen Bonding in Water Water could be considered as the "perfect" hydrogen bonded system. Each Oygen (O) has 2 lone pairs of electrons therefore, 4 Hydrogen bonds (H-bonds) can be formed. Hydrogen-bonding network formed in liquid water is responsible for many of the essential and unique properties of water. Ice forms a crystalline lattice, held together by a multitude of H-bonds

7. Hydrogen Bonding in molecules the hydrogen is partially positive and attracted to the partially negative charge on the nitrogen. Nitrogen has only one lone pair, thus, only one hydrogen bond can be made to each nitrogen.

8. Activity

9. http://www.youtube.com/watch?NR=1&v=aH2IbYs_XjY

10. Experiment Plan and perform an investigation to identify and describe the effect of anti-freeze (ethylene glycol) or salt on the boiling point of water

11. How would you plan this experiment? Plan and perform an investigation to identify and describe the effect of anti-freeze (ethylene glycol) or salt on the boiling point of water

12. What safety steps need to be taken?

13. What is your hypothesis?

14. Collecting data

15. What can be concluded?

16. Blog Site: hydrogenbonding2y.blogspot.com Questions?